SC450

Service Manual
Advance SC450, 9087331020
Nilfisk SC450, 9087330020 - 9087370020
Nilfisk SC450, 9087332020 - 9087372020

English

11-12 - Revised 4-14 (2)

Form No. 9099600000
Service Manual – SC450 Index 2

Index
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Machine General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Service Manual Purpose and Field of Application . . . . . . . . . . . . . . . . . . . . . . . 4
Other Reference Manuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Service and Spare Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Serial Number Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
General Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Machine Lifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Machine Transportation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Machine Nomenclature Battery Version (know your machine) . . . . . . . . . . . . . . . 10
Control Panel Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Machine Nomenclature Cable Version (know your machine) . . . . . . . . . . . . . . . . 13
Control Panel Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Service and Diagnostic Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Technical Data Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Technical Data Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Scheduled Maintenance Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Control System - Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Connectors on the Function Electronic Board . . . . . . . . . . . . . . . . . . . . . . . . 27

Control System - Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Electrical System - Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Fuses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Machine Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Electrical System - Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Service Manual – SC450 Index 3

Recovery System - Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Recovery System - Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Scrub System, Disc - Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Scrub System, Disc - Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Solution System - Battery Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Solution System - Cable Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Wiring Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Service Manual – SC450 Index 4

Squeegee System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Maintenance and Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

Wheel System, Non-Traction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Component Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Service Manual – SC450 General Information 5

General Information

Machine General Description

The SC450 is a “walk behind” industrial machine designed to wash and dry floors, in civil or industrial envi-
ronments, in one pass. The machine is powered by on-board batteries (Battery version) and with electric mains
via power supply cable (cable version). The machine is equipped with a single disc brush, a controlled solution
flow dosing system and a rear squeegee with blades, which dries the floor by vacuuming the dirty water.

Service Manual Purpose and Field of Application

This document is a technical resource intended to help service technicians when carrying out maintenance
and repairs on the SC450, to guarantee the best cleaning performance and a long working life for the machine.
Please read this manual carefully before performing any maintenance and repair procedure on the machine.

Other Reference Manuals

Model Product Code Intruction for Use Spare Parts List
Advance SC450 - BATTERY 9087331020 9099602000 9099603000
Nilfisk SC450 - BATTERY 9087330020 - 9087370020 9099589000 9099590000
Nilfisk SC450 - CABLE 9087332020 - 9087372020 9099596000 9099597000

Assembly Instructions Instruction Code Machines concerned

BATTERY CHARGER KIT 909 6746 000 Nilfisk SC450
20” SPLASH SHIELD KIT 909 6736 000 Nilfisk / Advance SC450
HANDLE BAR GREY KIT 9100000465 Nilfisk / Advance SC450

These manuals are available at:

- Local Nilfisk-Advance Retailer
- Nilfisk-Advance website: www.nilfisk.com - www.advance-us.com
Service Manual – SC450 General Information 6

Conventions
Forward, backward, front, rear, left or right are intended with reference to the operator’s position, that is to
say in driving position with the hands on the handlebar.

Service and Spare Parts

Service and repairs must be performed only by authorised personnel or Nilfisk Service Centers. The authorised
personnel is trained directly at the manufacturer’s premises and has original spare parts and accessories.
Contact Nilfisk Retailer indicated below for service or to order spare parts and accessories, specifying the ma-
chine model and serial number.

(Please, apply Retailer label here)

Serial Number Label

The model name and serial number are marked on
the plate (see the example to the side).
Product number and year of production are marked
on the same plate.
This information is useful when requiring machine
spare parts.
Use the following table to write down the machine
identification data.

Model: Scrubber-Dryer SC450 20 B Serial No: ..................

Prod. Nr: 9087331020 Date code: .......
GVW: 190 kg/419 lb IPX4 LpA = 68 dB(A)
37 A Charg.100-240Vac 50-60 Hz Battery 24 Vdc
Type E Floor cleaning machine
Conform to:
UL STD 583

Certified to: 2%
CSA STD C22.2 N.68-92 3084826

“Made in Hungary”
Nilfisk-Advance, Inc.
Plymouth, MN, USA
A Nilfisk-Advance Brand www.advance-us.com

P200001

Model ................................................................................................................

Product Nr. .......................................................................................................

Serial No. ..........................................................................................................

Service Manual – SC450 General Information 7

Safety
The following symbols indicate potentially dangerous situations. Always read this information carefully and
take all necessary precautions to safeguard people and property.

Symbols
Danger! It indicates a dangerous situation with risk of death for the operator.

Warning! It indicates a potential risk of injury for people or damage to objects.

Caution! It indicates a caution related to important or useful functions.

Note: It indicates a remark related to important or useful functions.

General Instructions
Specific warnings and cautions to inform about potential damages to people and machine are shown below.

Warning! Make sure to follow the safety precautions to avoid situations that may lead to
serious injuries.

–– This machine must be used by properly trained operators only.

–– Do not wear jewels when working near electrical components.
–– Do not work under the lifted machine, if it is not securely fixed.
–– Do not operate the machine near toxic, dangerous, flammable and/or explosive powders, liquids
or vapors. This machine is not suitable for collecting dangerous powders.
–– BATTERY Version - Before performing any cleaning, maintenance, repair or replacement pro-
cedure, turn the machine main switches to “0” and disconnect the battery connector.
–– (For WET batteries only). Keep the battery away from sparks, flames and incandescent material.
During the normal operation explosive gases are released.
–– (For WET batteries only). Battery charging produces highly explosive hydrogen gas. Keep the
battery cover open during battery charging and perform this procedure in well-ventilated areas
and away from naked flames.
–– CABLE Version - Before performing any maintenance, repair, cleaning or replacement proce-
dure disconnect the plug from the electrical mains.
Service Manual – SC450 General Information 8

Caution! Make sure to follow the safety precautions to avoid situations that may lead to
serious injuries, damages to materials or equipments.

–– Carefully read all the instructions before performing any maintenance/repair procedure.
–– Always protect the machine against the sun, rain and bad weather, both under operation and
inactivity condition. Store the machine indoors, in a dry place.
–– Before using the machine, close all doors and/or covers.
–– This machine is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge, unless they have been given
supervision or instruction concerning use of the machine by a person responsible for they safety.
Children should be supervised to ensure that they do not play with the machine.
–– Close attention is necessary when used near children.
–– Use only as shown in this Manual. Use only Nilfisk’s recommended accessories.
–– Check the machine carefully before each use, always check that all the components have been as-
sembled before use. If the machine is not perfectly assembled it can cause damages to people and
properties.
–– Take all necessary precautions to prevent hair, jewels and loose clothes from being caught by the
machine moving parts.
–– Do not use the machine on slopes with a gradient exceeding the specifications.
–– Do not use the machine on incline.
–– Do not tilt the machine more than the angle indicated on the machine itself, in order to prevent
instability.
–– Do not use the machine in particularly dusty areas.
–– Use the machine only where a proper lighting is provided.
–– While using this machine, take care not to cause damage to people or objects.
–– Do not bump into shelves or scaffoldings, especially where there is a risk of falling objects.
–– Do not lean liquid containers on the machine, use the relevant can holder.
–– The machine working temperature must be between 0°C and +40°C.
–– The storage temperature must be between 0°C and +40°C.
–– The humidity must be between 30% and 95%.
–– When using floor cleaning detergents, follow the instructions on the labels of the detergent
bottles.
–– To handle floor cleaning detergents, wear suitable gloves and protections.
–– Do not use the machine as a means of transport; do not push/tow it.
–– Do not allow the brush/pad to operate while the machine is stationary to avoid damaging the
floor.
–– In case of fire, use a powder fire extinguisher, not a water one.
–– Do not tamper with the machine safety guards and follow the ordinary maintenance instructions
scrupulously.
–– Do not allow any object to enter into the openings. Do not use the machine if the openings are
clogged. Always keep the openings free from dust, hairs and any other foreign material which
could reduce the air flow.
–– Do not remove or modify the plates affixed to the machine.
–– This machine cannot be used on roads or public streets.
–– Pay attention during machine transportation when temperature is below freezing point. The
water in the recovery tank or in the hoses could freeze and seriously damage the machine.
–– Use only brushes supplied with the machine or those specified in the Instrucion for use manual.
Using other brushes could reduce safety.
–– If parts must be replaced, require ORIGINAL spare parts from an Authorised Dealer or Retailer.
–– Do not wash the machine with direct or pressurised water jets, or with corrosive substances.
–– The machine must be disposed of properly, because of the presence of toxic-harmful materials
(batteries, oils, etc.), which are subject to standards that require disposal in special centres.
Service Manual – SC450 General Information 9

–– BATTERY Version - Before using the battery charger, ensure that frequency and voltage val-
ues, indicated on the machine serial number plate, match the mains voltage.
–– Do not pull or carry the machine by the battery charger cable and never use the battery charger
cable as a handle. Do not close a door on the battery charger cable, or pull the battery charger
cable around sharp edges or corners. Do not run the machine on the battery charger cable.
–– To reduce the risk of fire, electric shock, or injury, do not leave the machine unattended when it
is plugged in.
–– Keep the battery charger cable away from heated surfaces.
–– (Before performing any maintenance procedure, disconnect the battery charger cable from the
electrical mains to avoid any risk of fire, electric shock or injuries.
–– Do not smoke while charging the batteries.
–– (For WET batteries only). When lead (WET) batteries are installed on the machine, do not tilt
the machine for more than 30° from the horizontal plane to prevent the highly corrosive acid
from leaking out of the batteries. If the machine must be tilted to perform any maintenance pro-
cedure, remove the batteries.
–– CABLE Version - The machine power supply cable is grounded and the relevant plug is ground-
ed too. In case of machine malfunction or breakdown, grounding connection reduces the risk of
electric shock.
–– The power supply cable plug must be connected to an appropriate outlet, which is grounded ac-
cording to law in force.
–– Improper connection can cause electric shock. Consult a qualified technician to make sure that
the outlet is properly grounded.
–– Do not tamper with the power supply cable plug. If the power supply cable plug cannot be con-
nected to the outlet, have new grounded outlet installed by a qualified technician, according to
the law in force.
–– Before connecting the power supply plug to the electrical mains, check that frequency and volt-
age, shown on the machine serial number plate, match the electrical mains voltage.
–– Do not handle the plug or the machine with wet hands.
–– Turn off all controls before unplugging.
–– Regularly check the power supply cable for damages, cuts, cracks and wear. If necessary, replace
it.
–– If the power supply cable is damaged, it must be replaced by the Manufacturer or by an autho-
rised Service Centre.
–– Do not pull or carry the machine by the power supply cable and never use the power supply cable
as a handle. Do not close a door on the power supply cable, or pull the power supply cable around
sharp edges or corners. Do not run the machine on the power supply cable.
–– The rotating brush must not come into contact with the power supply cable.
–– Keep the supply cable away from heated surfaces.
–– To reduce the risk of fire, electric shock, or injury, do not leave the machine unattended when it
is plugged in. Disconnect the machine from the electrical mains when not in use and before per-
forming maintenance procedures.
–– In case of machine malfunctions, ensure that these are not due to lack of maintenance. If neces-
sary, request assistance from the authorised personnel or from an authorised Service Center.
–– If the machine
–– does not work properly
–– is damaged
–– has water or foam leaks
–– has been left outdoors exposed to bad weather conditions
–– is wet or has been dropped into water
–– turn it off immediately and contact the Nilfisk Service Center or a qualified technician.
Service Manual – SC450 General Information 10

Machine Lifting
Warning! Do not work under the lifted machine, if it is not securely fixed.

Machine Transportation
Warning! Before transporting the machine, make sure that:

All covers are closed.

The solution and recovery tanks are emptied.

The batteries are disconnected.

The machine is securely fastened to the means of transport.

Service Manual – SC450 General Information 11

Machine Nomenclature Battery Version (know your machine)

Battery charger data Control panel

inspection window
Can holder
Handlebar
Recovery tank
Battery charger cable cover

Battery charger
cable holder Recovery
Squeegee tank
lifting/lowering lever
Solution
tank
Battery Serial number
connector (red) plate/technical
data/conformity
certification

Solution drain Brush

and level check hose deck

Recovery water Brush

drain hose
Front wheels on fixed axle
Squeegee
Rear parking wheel
Squeegee
mounting Squeegee
handwheel Squeegee mounting
balance handwheel
Squeegee adjusting
vacuum handwheel
hose
P200002
Service Manual – SC450 General Information 12

Machine Nomenclature Battery Version (Continues)

Recovery tank cover
Tank (completely opened)
cover
gasket Recovery tank cover
(half-open)

Vacuum grid with

automatic
shut-off float 12V

12V
Water
removable
filler hose
Battery connection
diagram
Solution Battery
filler neck caps

Machine
Vacuum in parking
system motor position

Batteries
Foam filter

Solenoid valve

Machine straight forward Solution ECO position of the solution

movement adjusting filter flow control lever
handwheel Machine forward
speed adjusting
handwheel
Front wheels Solution flow
on fixed axle control lever
P200003
Service Manual – SC450 General Information 13

Control Panel Battery Version

Green LED - charged battery Brush switch Vacuum system switch
Yellow LED - semi-discharged battery
Red LED - discharged battery
Brush enabling Brush enabling
push-button push-button

%
max.2

Battery charge
LEDs indicator

Green warning light

(the battery charger is
on and batteries are
charged)
Yellow warning light
(the battery charger is
on and batteries are
semi-discharged) Electronic battery Lead (WET) or gel (GEL)
charger battery selector
Red warning light (the battery
charger is on and it is charging
the batteries)
P200004
Service Manual – SC450 General Information 14

Machine Nomenclature Cable Version (know your machine)

Handlebar Control panel
Can holder Recovery tank
cover
Power supply cable holder
Power supply cable Recovery
tank

Squeegee
lifting/lowering lever Solution
tank
Serial number
Solution drain plate/technical
and level check hose data/conformity
certification

Recovery water
drain hose Brush
deck
Squeegee
Brush
Squeegee
Front wheels on fixed axle
mounting
handwheel Rear parking wheel
Squeegee Squeegee
vacuum balance
hose adjusting
handwheel
P200002E
Service Manual – SC450 General Information 15

Machine Nomenclature Cable Version (Continues)

Recovery tank cover
Tank (completely opened)
cover
gasket Recovery tank cover
(half-open)

Vacuum grid with

automatic
shut-off float

Water
removable
filler hose

Solution Recovery tank mounting

filler neck screws (do not remove!)

Machine
Vacuum in parking
system motor position

Batteries
Foam filter

Solenoid valve

Machine straight forward Solution ECO position of the solution

movement adjusting filter flow control lever
handwheel Machine forward
speed adjusting
handwheel
Front wheels Solution flow
on fixed axle control lever
P200003E
Service Manual – SC450 General Information 16

Control Panel Cable Version

Interruttore spazzola Interruttore impianto di
aspirazione

Pulsante di azionamento Pulsante di azionamento

spazzola spazzola

%
max.2

P200004E
Service Manual – SC450 General Information 17

Service and Diagnostic Equipment

Besides a complete set of standard meters, the following instruments are necessary to perform fast checks,
maintenance and repairs on Nilfisk-Advance machines:
Besides a complete set of standard meters, the following instruments are necessary to perform fast checks and
repairs on Nilfisk-Advance machines:
• Laptop computer charged with the current version of EzParts, Adobe Reader and (if possible) Internet
connection
• Digital Volt Meter (DVM)
• Amperometric pliers with possibility of making DC measurements
• Hydrometer
• Battery charge tester to check 12V batteries
• Static control wrist strap
• Dynamometric wrench set
• A copy of the Instruction for use and Spare Parts List of the machine to be serviced (provided with the
machine or available at www.advance-us.com or other Nilfisk-Advance websites).

The following equipment is also available at Nilfisk-Advance Centers:

• Vacuum water lift gauge, P/N 56205281
Service Manual – SC450 General Information 18

Technical Data Battery Version

Advance Nilfisk
Descriptions / Model
SC450 20B SC450 53B
Solution tank capacity 10.5 US gal (40 liters)
Recovery tank capacity 11.9 US gal (45 liters)
Machine length 46.4 in (1,180 mm)
Machine width without squeegee 22 in (559 mm)
Machine height 41.7 in (1,060 mm)
Cleaning width 20 in (530 mm)
Squeegee width 30 in (760 mm)
Brush diameter 20 in (530 mm)
Diameter of wheels on fixed axle 10 in (254 mm)
Wheel pressure on the floor 710 psi (4.9 N/mm2)
Brush pressure with full tank and lowered squeegee 66 lb (30 kg)
Min/max solution flow 0.10÷0.42 gpm (0.4÷1.6 liters/min)
ECO solution flow 0.10 gpm (0.4 liters/min)
Sound pressure level at workstation (ISO 11201, ISO 4871, EN 60335-2-72) (LpA) 68 dB(A) ± 3 dB(A)
Machine sound pressure level (ISO 3744, ISO 4871, EN 60335-2-72) (LwA) 86 dB(A)
Vibration level at the operator’s arms (ISO 5349-1, EN 60335-2-72) < 98.4 in/s2 (< 2.5 m/s2)
Maximum gradient when working 2%
IP protection class X4
Protection class (electric) III
Vacuum power 0.44 hp (330 W)
Vacuum water lift (blocked) 43.3 inH2O (1,100 mmH2O)
Brush motor power 0.64 hp (480 W)
Brush rotation speed 154 rpm
Total absorbed power 34 A (0.8 kW)
Battery compartment size (width x length x height) 350 x 350 x 300 mm (13.7 x 13.7 x 11.8 in)
Battery voltage 24 V
Standard batteries (2) Dry: 12 V 70 Ah C5
Battery charger 100-240 VAC
Work autonomy (standard batteries) 2 hour
Weight without batteries and with empty tanks 167 lb (76 kg) 154 lb (70 kg)
Gross vehicle weight (GVW) 419 lb (190 kg) 419 lb (190 kg)
Shipping weight 227 lb (103 kg) 214 lb (97 kg)
Service Manual – SC450 General Information 19

Technical Data Cable Version

Nilfisk
Descriptions / Model
SC450 53E
Solution tank capacity 10.5 US gal (40 liters)
Recovery tank capacity 11.9 US gal (45 liters)
Machine length 46.4 in (1,180 mm)
Machine width without squeegee 22 in (559 mm)
Machine height 41.7 in (1,060 mm)
Cleaning width 20 in (530 mm)
Squeegee width 30 in (760 mm)
Brush diameter 20 in (530 mm)
Diameter of wheels on fixed axle 10 in (254 mm)
Wheel pressure on the floor 710 psi (4.9 N/mm2)
Brush pressure with full tank and lowered squeegee 66 lb (30 kg)
Min/max solution flow 0.10÷0.42 gpm (0.4÷1.6 liters/min)
ECO solution flow 0.10 gpm (0.4 liters/min)
Sound pressure level at workstation (ISO 11201, ISO 4871, EN 60335-2-72) (LpA) 70 dB(A) ± 3 dB(A)
Machine sound pressure level (ISO 3744, ISO 4871, EN 60335-2-72) (LwA) 89 dB(A)
Vibration level at the operator’s arms (ISO 5349-1, EN 60335-2-72) < 98.4 in/s2 (< 2.5 m/s2)
Maximum gradient when working 2%
IP protection class X4
Protection class (electric) I
Vacuum power 0.44 hp (550 W, 50-60 Hz)
Vacuum water lift (blocked) 47.2 inH2O (1.200 mm H2O)
Brush motor power 0.64 hp (1,100 W 50-60 Hz)
Brush rotation speed 150 rpm
Total absorbed power 7.5 A (1.7 kW)
Power supply 230 V - 50-60 Hz
Weight without batteries and with empty tanks 207 lb (94 kg)
Gross vehicle weight (GVW) 273 lb (124 kg)
Shipping weight 266 lb (121 kg)
Service Manual – SC450 General Information 20

Dimensions

41.7 in (1,060 mm )
46.4 in (1,180 mm) 30 in (760 mm)

P200005
Service Manual – SC450 General Information 21

Maintenance
The lifespan of the machine and its maximum operating safety are ensured by correct and regular mainte-
nance.

Warning! Read carefully the instructions in the Safety chapter before performing any
maintenance procedure.

The following table provides the scheduled maintenance. The intervals shown may vary according to particu-
lar working conditions, which are to be defined by the person in charge of the maintenance.
For instructions on maintenance procedures, see the following paragraphs.

Scheduled Maintenance Table

Daily, after using Every six
Procedure Weekly Yearly
the machine months
Battery charging (battery version)
Squeegee cleaning
Brush/pad cleaning
Tank and vacuum grid with float cleaning, and cover
gasket check
Power supply cable check (cable version)
Squeegee blade check and replacement
Solution filter cleaning
WET battery fluid level check
Brush/pad-holder motor carbon brush check or
replacement (battery version)
Vacuum system motor carbon brush check or
replacement
Service Manual – SC450 Control System - Battery Version 22

Control System - Battery Version

Functional Description
The function control is performed directly by the brush switch (SW1), the vacuum system switch (SW2) and
the brush activation push-buttons (SW3 with SW4).
The switches (SW1) and (SW2) power the function electronic board (EB1).
The control circuits are protected by the fuse (F3) on the function electronic board (EB1).
The battery voltage is shown on the electronic board LED (EB2).

Wiring Diagram

J2.7 - Power supply (+)

ELECTRONIC BOARD
LED (EB2)
SOLENOID VALVE AND
VACUUM SYSTEM BRUSH ELECTRONIC BOARD FUSE (F3)
SWITCH (SW2) SWITCH (SW1)

J1.1 - Switch power supply

J1.6 - Green LED - J1.1
J1.5 - Yellow LED - J1.2

J1.8 - Brush system Switch J1.4 - Red LED - J1.3

J1.7 - Common LED + J1.4

FUNCTION
ELECTRONIC BOARD (EB1)
J1.2 - Brush switch activation SOLUTION SOLENOID
VALVE (EV1)
BRUSH ACTIVATION J3.1 - Solenoid valve (+)
PUSH-BUTTONS (SW3 with SW4)
J1.3 - Vacuum system switch
CONNECTOR (C2) J3.2 - Solenoid valve (-)
F1 - Battery charger power supply
J2.5 - Brush motor current detection (+)
J2.3 - Vacuum system relay power supply
J2.4 - Brush motor current detection (-)
J2.2 - Brush relay power supply
VACUUM SYSTEM
MOTOR RELAY (ES2) J2.1 - Relay power supply
BRUSH MOTOR
ELECTROMAGNETIC J2.6 - Power supply (-)
SWITCH (ES1)

P200006
Service Manual – SC450 Control System - Battery Version 23

Component Location
• Brush switch (SW1)
• Vacuum system switch (SW2)
• Brush activation push-button (SW3)
• Battery voltage LEDs
• Function electronic board (EB1)
• LED electronic board (EB2)
• Wiring harness

Battery voltage LEDs Brush switch (SW1)

Vacuum system switch (SW2)

Brush activation
*SW4(
push-buttons (SW3) (SW4)

LED Function
electronic electronic
board (EB2) board (EB1)

Wiring harness

P200007
Service Manual – SC450 Control System - Battery Version 24

Removal and Installation

Function Electronic Board Disassembly/Assembly

Disassembly

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Move aside the recovery water drain hose.

4. Remove the battery charger cable, if equipped, from the cable holder.

5. Remove the screws (A).

6. Carefully move the panel (B) by disengaging the wiring harness grommet (C) from its housing.

7. Disconnect the connectors (D) of the function electronic board (E).

8. Disengage the four fasteners (F) and remove the function electronic board (E).

Assembly

9. Assemble the components in the reverse order of disassembly, and note the following:
• When installing a new function electronic board (E), set the following:
–– battery charger on board (Ch) or not (NO Ch), with the selector (G)
–– battery type, Pb (Wet) or Gel, with the selector (H)

F D D
F

A A

D
F
F D
G H
A
C

P200008
Service Manual – SC450 Control System - Battery Version 25

Brush Activation Push-Button Disassembly/Assembly (old version)

Disassembly

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Remove the screws (A) and move the brush activation push-button (B).

4. Loosen the ring nut (C) off the bulkhead connection and push the cable (D) inside the handlebar as much
as possible, then pull the cables (E) with the joints (F) of the push-button (B).

5. Cut the cables (E) on the joints (F) and retrieve the push-button (B).

Assembly

6. Assemble the components in the reverse order of disassembly, and note the following:
• Restore the connections (F) by using the joints supplied with the push-button.
• Before tightening the ring nut (C) push the cable (D) inside the handlebar as much as possible.

E
A B A

F
D

B
P200009
Service Manual – SC450 Control System - Battery Version 26

Brush Activation Push-Button Disassembly/Assembly (new version)

Smontaggio

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Remove the screws (A) and move the brush activation push-button (B).

4. Loosen the ring nut (C) off the bulkhead connection and push the cable (D) inside the handlebar as much
as possible, then pull the cables (E) with the connectors (F) of the push-buttons (B).
5. Disconnect the connectors (F) and retrieve the push-buttons (B).

Assembly

6. Assemble the components in the reverse order of disassembly, and note the following:
• Before tightening the ring nut (C) push the cable (D) inside the handlebar as much as possible.

A B A F E A B F E

P200009B
Service Manual – SC450 Control System - Battery Version 27

Specifications

Function Electronic Board Specifications

The function electronic board performs the following:

a. BRUSH MOTOR PROTECTION: By reading the voltage drop across (F1) fuse, the main brush
motor amperage (M1) is monitored. If the voltage drop is higher than 40 mV, the 3 LEDs on the LED
electronic board (EB2) start flashing simultaneously. If this condition persists, after a time inversely
proportional to the value of voltage drop detected, the brush motor is stopped. To reset the protection,
the electronic board must be turned off and on with the switches (SW1) and (SW2).

b. BATTERY PROTECTION: Battery charge status is shown by the 3 LEDs on the LED electronic
board (EB2), depending on the type of battery (WET/GEL) according to the following diagram:

WET GEL
Green LED on (fixed) V>21.0 V>22.3
Yellow LED on (fixed) 21.0>V>20.3 22.3>V>21.6
Red LED flashing V>20.3 V>21.6

When the red LED starts flashing, brush and vacuum system functions are automatically deactivated.

c. PROCEDURE FOR BATTERY SETTING (WET/GEL): on the electronic board there is a dip-switch
with 2 positions, marked as “WET” and “GEL”.
Service Manual – SC450 Control System - Battery Version 28

Connectors on the Function Electronic Board

F1 J1

J3

J2

P200010

J1 - 8 WAY-CONNECTOR
PIN Description Voltage Ref. to B -
1 CS Switch power supply 24V
2 BS Brush switch activation 24V
3 VS Vacuum system switch 24V
4 LR Red LED (<=> EB2 PIN 2) 0V
5 LG Yellow LED (<=> EB2 PIN 3) 0V
6 LV Green LED (<=> EB2 PIN 4) 0V
7 LC Common LED (<=> EB2 PIN 1) 5V
8 KY Brush system switch 24V

J2 - 8 WAY-CONNECTOR
PIN Description Voltage Ref. to B -
1 CT Relay power supply 24V
2 BT Brush relay power supply 0V
3 VT Vacuum system relay power supply 0V
4 S- Brush motor current detection - 0V
5 S+ Brush motor current detection + 0V
6 V- Power supply - 0V
7 V+ Power supply + 24V
8 BL Not used -

J3 - 3 WAY-CONNECTOR
PIN Description Voltage Ref. to B -
1 W+ Solenoid valve + 24V
2 W- Solenoid valve - 0V

F1 - FASTON
PIN Description Voltage Ref. to B -
1 6.3 mm Power supply from battery charger 24V 24V 24V (*)
2 4.8 mm Not used -
Service Manual – SC450 Control System - Cable Version 29

Control System - Cable Version

Functional Description
The function control is performed directly by the brush switch (SW1), the vacuum system switch (SW2) and
the brush activation push-buttons (SW3 with SW4).
The switches (SW1) and (SW2) power the function electronic board (EB1).

Wiring Diagram

MAINS FILTER (FL1)

BRUSH ACTIVATION
PUSH-BUTTONS (SW3) (SW4)

HANDLE BAR SWITCHES

(SW3) (SW4)

VACUUM SWITCH (SW2)

BRUSH MOTOR RELAY (ES1)

VACUUM MOTOR (M2)

P200006C
Service Manual – SC450 Control System - Cable Version 30

Component Location
• Brush switch (SW1)
• Vacuum system switch (SW2)
• Brush activation push-buttons (SW3) (SW4)
• Mains filter (FL1)
• Brush motor relay (ES1)

Brush switch (SW1)

Vacuum system switch (SW2)

Brush activation
*SW4(
push-buttons (SW3) (SW4)

Mains filter (FL1)

Wiring harness

Brush motor
relay (ES1)

P200007
Service Manual – SC450 Control System - Cable Version 31

Removal and Installation

Brush Activation Push-Button Disassembly/Assembly (old version)

Disassembly

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

1. Make sure that the power supply cable plug is disconnected from the electrical mains.

2. Remove the screws (A) and move the brush activation push-button (B).

3. Loosen the ring nut (C) off the bulkhead connection and push the cable (D) inside the handlebar as much
as possible, then pull the cables (E) with the joints (F) of the push-button (B).

4. Cut the cables (E) on the joints (F) and retrieve the push-button (B).

Assembly

5. Assemble the components in the reverse order of disassembly, and note the following:
• Restore the connections (F) by using the joints supplied with the push-button.
• Before tightening the ring nut (C) push the cable (D) inside the handlebar as much as possible.

E
A B A

F
D

B
P200009
Service Manual – SC450 Control System - Cable Version 32

Brush Activation Push-Button Disassembly/Assembly (new version)

Smontaggio

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

1. Make sure that the power supply cable plug is disconnected from the electrical mains.

2. Remove the screws (A) and move the brush activation push-button (B).

3. Loosen the ring nut (C) off the bulkhead connection and push the cable (D) inside the handlebar as much
as possible, then pull the cables (E) with the connectors (F) of the push-buttons (B).
4. Disconnect the connectors (F) and retrieve the push-buttons (B).

Assembly

5. Assemble the components in the reverse order of disassembly, and note the following:
• Before tightening the ring nut (C) push the cable (D) inside the handlebar as much as possible.

A B A F E A B F E

P200009B
Service Manual – SC450 Electrical System - Battery Version 33

Electrical System - Battery Version

Functional Description
Basically the electrical system consists of a function tor (C2) is disconnected from the electrical mains.
electronic board (EB1) which determines the brush When the battery charger is connected to the electri-
and vacuum system motor activation by means of the cal mains, the battery charger inner relay opens the
relevant switches (SW1) and (SW2), disabling them contact and stops the enabling signal on the yellow
when the battery voltage drops below the battery connector (C2). When the battery charger is not in-
safety threshold value. stalled, the yellow connector (C2) is not connected and
The battery is connected to the system by means of the dip-switch on the electronic board (EB1) must be
the ANDERSON POWER connector (C1). turned to “NO CH”.
The on-board battery charger (CH) is connected to the For further details, see the descriptions of individual
battery with the red (+) and black (-) connector (C2) sub-systems.
and supplies the enabling signal (+24V) to activate
the machine functions only when its yellow connec-

Fuses
The brush motor circuit is protected from short-cir- 30A blade fuse (F2).
cuits by the 40A fuse (F1). The motor is protected The solenoid valve (EV1) and the function electronic
from overloads by means of the electronic protection board (EB1) control circuits are protected by 5A blade
system described in the Function Electronic Board fuses (F3) on the function electronic board (EB1).
Specifications chapter.
The vacuum system motor circuit is protected by the

Wiring Diagram

CONNECTOR + (C1)

CONNECTOR (C2)

24V BATTERY BATTERY CHARGER (CH)

(BAT)

CONNECTOR (C2)
F1 - Battery charger power supply

FUNCTION ELECTRONIC
BOARD (EB1)
CONNECTOR (C2)

CONNECTOR - (C1)

P200011
Service Manual – SC450 Electrical System - Battery Version 34

Component Location
• Batteries (BAT) • Electrical component box
• Battery connections • Brush fuse (F1)
• Battery charger (CH) • Vacuum fuse (F2)
• Battery connector (C1) • Control/solenoid fuse (F3)

Control/solenoid fuse (F2)

Vacuum fuse (F3)
Brush fuse (F1)

Electrical component box

Battery charger (CH)

Battery connector (C1)

12V

12V

Batteries (BAT)

Battery
connections

P200012
Service Manual – SC450 Electrical System - Battery Version 35

Maintenance and Adjustments

Battery Installation And Battery Type Setting (WET or GEL/AGM)

Set the electronic board of the machine and of the battery charger (if equipped) according to the type of batter-
ies installed (WET or GEL/AGM) as shown below:

Machine Setting

1. Ensure the battery connector (A) is disconnected.

The machine factory setting is for GEL batteries. If this setting corresponds to the type of batteries
installed, go to step 7. Otherwise, perform steps 2 to 6.

2. Move aside the recovery water drain hose.

3. Remove the battery charger cable, if equipped, from the cable holder (B).

4. Remove the screws (C) and carefully move aside the panel (D) by disengaging the grommet (E) from its
housing on the panel (D).

5. Turn the microswitch (F) to WET position.

Warning! Do not move/set the adjacent switch (G).

6. Perform steps 2 to 5 in the reverse order.

C G F

C E

P200013
Service Manual – SC450 Electrical System - Battery Version 36

Battery Installation And Battery Type Setting (WET or GEL/AGM) (Continues)

Battery Charger Setting (for machines with on-board battery charger)

7. Remove the battery charger data inspection window screws (N).

8. Remove the window (H).

9. Turn the battery charger selector (I) to WET for lead batteries, or to GEL for GEL/AGM batteries.

10. Install the window (H) and tighten the screws (N).

Battery Installation

11. Remove the recovery tank cover (J).

12. Install the batteries (K) on the machine according to the diagram (L).

Warning! For a proper machine balance, install the batteries in the compartment, with the
shims (M) placed on the rear wall.

13. Install the recovery tank cover (J).

14. If necessary, charge the batteries (see the Battery charging paragraph).

N I J

H N
M
12V

12V

L
P200013
Service Manual – SC450 Electrical System - Battery Version 37

Battery Charging

Note: Charge the batteries when the yellow or red warning light on the control panel turns on,
or at the end of every working cycle.

Caution! Keeping the batteries charged make their life last longer.

Caution! When the batteries are discharged, charge them as soon as possible, as that
condition makes their life shorter. Check for battery charge at least once a week.

Caution! If the machine is not equipped with on-board battery charger, choose an external
battery charger suitable for the type of batteries installed.

Caution! WET battery charging produces highly explosive hydrogen gas. Charge the batteries
in well-ventilated areas and away from naked flames. Do not smoke while charging
the batteries.
Do not reinstall the recovery tank until the battery charging cycle is over.

Caution! Pay careful attention when charging WET batteries as there may be battery fluid
leakages. The battery fluid is corrosive. If it comes in contact with skin or eyes, rinse
thoroughly with water and consult a physician.

Caution! It indicates a caution related to important or useful functions.

1. Drive the machine to the appointed recharging area.

2. Turn off the machine by turning the switches to “0”.

3. For WET batteries only:

–– Tip up the recovery tank.
–– Check the level of electrolyte inside the batteries; if necessary, top up through the caps.
–– Leave all the battery caps open for next charging.
–– If necessary, clean the upper surface of the batteries.

4. Charge the batteries according to one of the following procedures, depending on the presence of the
electronic battery charger.
Service Manual – SC450 Electrical System - Battery Version 38

Battery Charging (Continues)

Charging the Batteries with an External Battery Charger

5. Check that the external battery charger is suitable by referring to the battery charger Manual. The
battery charger voltage rating must be 24 V.

6. Disconnect the battery connector (A) and connect it to the external battery charger.

7. Connect the battery charger to the electrical mains.

8. After charging, disconnect the battery charger from the electrical mains and from the battery connector (A).

9. (For WET batteries only): Check the level of electrolyte inside the batteries (B) and close all the caps (C).

10. Connect the battery connector (A) to the machine.

11. (For WET batteries only): Tip down the recovery tank.

A
P2000014B
Service Manual – SC450 Electrical System - Battery Version 39

Battery Charging (Continues)

Charging the Batteries with an (Optional) Battery Charger Installed on the Machine

12. Connect the battery charger cable (D) to the electrical mains (the electrical mains voltage and
frequency must be compatible with the battery charger values shown on the machine serial number
plate (E)).
When the battery charger is connected to the electrical mains, all machine functions are automatically
cut off.
If the warning light (F) on the battery charger control panel stays on, the battery charger is charging
the batteries.

13. When the green warning light (G) turns on, the battery charging is completed.

14. When the battery charging is completed, disconnect the battery charger cable (D) from the electrical
mains and wind it round its housing (H).

15. (For WET batteries only): Tip down the recovery tank.

Note: For further information about the battery charger operation, see the Battery charger
Manual.

D
G
H
F

E
P2000014
Service Manual – SC450 Electrical System - Battery Version 40

Fuse Check and Replacement

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Move aside the recovery water drain hose.

4. Remove the battery charger cable, if equipped, from the cable holder.

5. Remove the screws (A).

6. Carefully move the panel (B) by disengaging the wiring harness grommet (C) from its housing.

7. Check the following fuses for integrity:

–– (D) Brush deck fuse F1 (40 A)
–– (E) Vacuum system fuse F2 (30 A)
–– (F) Electronic board fuse F3 (5 A)

8. Replace the open fuse, when the component that caused deactivation has fully cooled down.

9. Engage the grommet (C) and install the cover (B), then tighten the screws.

10. Place the battery charger cable, if equipped, on the cable holder.

11. Connect the battery connector (red).

A A

E F D
B

A
C

P2000015
Service Manual – SC450 Electrical System - Battery Version 41

Charge condition display

TRANSITION THRESHOLD (VOLT)
INDICATION CONSEQUENCE
WET GEL
1 GREEN LED: fixed - YELLOW LED: fixed 22 V 22.2 V -
Brushes + Vacuum system
2 YELLOW LED: fixed - RED LED: flashing 20.4 V 21.6 V
OFF

Troubleshooting
Trouble Possible Causes Remedy
The machine is not working The batteries (BAT) are discharged or its connections are Charge the batteries or clean/repair
not efficient the connections
The batteries (BAT) are broken Check the battery no-load voltage
The battery charger (CH) is broken Replace

The fuses (F1, F2, F3) are open Replace

The wiring harness is cut or pressed or short circuited Repair

Service Manual – SC450 Electrical System - Battery Version 42

Machine Wiring Diagram

CONNECTOR + (C1)

VACUUM SYSTEM
MOTOR FUSE (F2)
CONNECTOR (C2)

ELECTRONIC BOARD
LED (EB2)
VACUUM SYSTEM BRUSH FUNCTION ELECTRONIC
SWITCH (SW2) SWITCH (SW1) BOARD (EB1)

BRUSH
MOTOR (M1)

24V BATTERY
(BAT)

+ SOLENOID VALVE AND

ELECTRONIC BOARD
FUSE (F3)

- VACUUM SYSTEM
BRUSH ACTIVATION MOTOR (M2)
PUSH-BUTTONS (SW3) (SW4)

CONNECTOR (C2) SOLUTION SOLENOID BRUSH MOTOR

VALVE (EV1) ELECTROMAGNETIC
SWITCH (ES1)

CONNECTOR (C2) VACUUM SYSTEM

MOTOR RELAY (ES2)
VACUUM SYSTEM BRUSH MOTOR
BATTERY CHARGER (CH) MOTOR RELAY (ES2) FUSE (F1)

BRUSH MOTOR ELECTROMAGNETIC

SWITCH (ES1)

CONNECTOR - (C1)
P2000016
Service Manual – SC450 Electrical System - Battery Version 43

Specifications
Advance Nilfisk
Descriptions / Model
SC450 20B SC450 53B
Total absorbed power 34 A (0.8 kW)
Battery compartment size (width x length x height) 350 x 350 x 300 mm (13.7 x 13.7 x 11.8 in)
Battery voltage 24 V
Standard batteries (2) Dry: 12 V 70 Ah C5
Battery charger 100-240 VAC
Work autonomy (standard batteries) 2 hour
Service Manual – SC450 Electrical System - Cable Version 44

Electrical System - Cable Version

Wiring Diagram

MAINS PLUG (PL) MAINS FILTER (FL1)

BRUSH SWITCH (SW1) VACUUM SWITCH (SW2)

BRUSH ACTIVATION
HEART SCREW (HS)
PUSH-BUTTONS (SW3) (SW4)

BRUSH MOTOR RELAY (ES1)

SUPPRESSION
FILTER (C1)

SOLENOID VALVE (EV1)

DISC BRUSH MOTOR (M1) VACUUM MOTOR (M2)

P200011C
Service Manual – SC450 Electrical System - Cable Version 45

Specifications
Nilfisk
Descriptions / Model
SC450 53E
Total absorbed power 7.5 A (1.7 kW)
Power supply 230 V - 50-60 Hz
Service Manual – SC450 Recovery System - Battery Version 46

Recovery System - Battery Version

Functional Description
The water recovery system removes the dirty water The automatic float in the vacuum grid stops vacuum
from the floor and pipes it to a recovery tank. When system motor (M2) from collecting any liquids.
the machine is running, the dirty water on the floor is When the automatic float closes and shuts down the
collected by the squeegee blades and collected through vacuum system, the vacuum system motor noise will
the slots in the same, piped through the vacuum hose increase and the floor will not be dried.
and into the tank by the airflow created by vacuum When the recovery tank is full it can be emptied
motor (M2). The dirty water is piped into the recovery through the drain hose.
tank, while the airflow continues to the vacuum fan.
The vacuum system motor (M2) is supplied by the
relay (ES2) which is driven by the electronic board
(EB1) when the switch (SW2) is closed. The circuit is
protected by the vacuum fuse (F2).

Wiring Diagram

VACUUM SYSTEM
J2.7 - Power supply (+) MOTOR FUSE (F2)

FUNCTION ELECTRONIC
VACUUM SYSTEM BOARD (EB1)
SWITCH (SW2)
24V
J1.1 - Switch power supply

SOLENOID VALVE AND

ELECTRONIC BOARD
FUSE (F3)

VACUUM SYSTEM
MOTOR (M2)

J1.3 - Vacuum system switch

24V
J2.3 - Vacuum system relay
power supply

VACUUM SYSTEM
B- MOTOR RELAY (ES2)
J2.1 - Relay power supply
VACUUM SYSTEM
MOTOR RELAY (ES2)
J2.6 - Power supply (-)

P200017
Service Manual – SC450 Recovery System - Battery Version 47

Component Location
• Recovery tank • Vacuum system motor (M2)
• Vacuum grid with automatic shut-off float • Electrical component box
• Recovery tank cover • Vacuum fuse (F2)
• Cover gasket • Relay (ES2)
• Recovery water drain hose
• Recovery water vacuum hose

Fuse (F2)

Relay (ES2)
Electrical
component box
Cover gasket

Recovery water
drain hose Recovery water
vacuum hose

Recovery tank cover

Vacuum grid with

Recovery tank
automatic shut-off
float

Vacuum system
motor (M2)

P200018
Service Manual – SC450 Recovery System - Battery Version 48

Maintenance and Adjustments

Tank and Vacuum Grid Cleaning

1. Drive the machine to the appointed disposal area.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Discharge the recovery water from the relevant tank.

4. Open the recovery tank cover (A), then clean and wash the cover, the tank (B) and the vacuum grid (C)
with clean water.
If necessary, remove the grid (C) clean it carefully and reinstall it.
If necessary, clean also the solution tank.
Drain the water from the tanks with the relevant drain hoses.

5. Check the recovery tank cover gasket (D) for integrity.

The gasket (D) must be in good shape, as it is necessary for the recovery tank stay sealed.
If necessary replace the gasket (D) by removing it from its housing. When assembling the new gasket,
install its junction (E) in the central rear area as shown in the figure.

6. Check that the seating surface (F) of the gasket (E) is integral and adequate for the gasket itself.

7. Close the recovery tank cover (A).

A F

B
P200019
Service Manual – SC450 Recovery System - Battery Version 49

Troubleshooting
Trouble Possible Causes Remedy

The vacuum system motor does not turn The vacuum system motor carbon brushes are worn Replace
on
The switch (SW2) is broken Replace

The vacuum system motor is faulty Check the amperage.

Check the carbon brushes.

Replace.

The vacuum fuse (F2) is blown Replace

The relay (ES2) is broken Replace

The recovery water vacuuming is The vacuum grid with automatic shut-off float is activated Drain the recovery tank
insufficient or there is no vacuuming because the recovery tank is full

The vacuum grid is dirty Clean

The tank cover is not correctly positioned Adjust

The tank cover gasket is not efficient Clean/replace

The vacuum system motor filter is dirty Clean

The vacuum gaskets are damaged or do not match Repair or replace

perfectly

The squeegee vacuum hose is broken Replace

The recovery tank vacuum hose is broken Replace

Service Manual – SC450 Recovery System - Battery Version 50

Removal and Installation

Vacuum System Motor Amperage Check

Warning! This procedure must be performed by qualified personnel only.

1. Check that the squeegee and the vacuum hose are clean and that there is no dirt in their inner parts.

2. Keep the squeegee lifted.

3. Remove the recovery water tank.

Warning! Do not touch uncovered electrical components while performing the following steps.

4. Apply the Amp clamp (A) on the battery cable (B).

5. Turn on the vacuum system and check that the vacuum system motor amperage is 13 - 17 A at 24 V.
Turn off the vacuum system.
Remove the Amp clamp (A).
If the amperage is higher, perform the following procedures to detect and correct the abnormal input:
• Check that the vacuum fuse (F2) is properly positioned
• Check the condition of the vacuum system motor carbon brushes
• Remove the vacuum system motor (see the procedure in the Vacuum System Motor Disassembly/As-
sembly paragraph), and check the condition of all its components.

If the above-mentioned procedures do not produce the correct readings for the vacuum system motor
amperage, the motor must be replaced (see the procedure in the Vacuum System Motor Disassembly/
Assembly paragraph).

Reassemby
6. Assemble the components in the reverse order of disassembly.

B
P200020
Service Manual – SC450 Recovery System - Battery Version 51

Vacuum System Motor Carbon Brush Check/Replacement

Disassembly/Check

1. Remove the vacuum system motor (see the procedure in the Vacuum System Motor Disassembly/
Assembly paragraph).

2. At the workbench, remove the sealing ring (A) from the vacuum system motor (B).

3. Remove the fan cover (C) by disengaging its inner fasteners.

4. With a proper tool, remove the soldering (D) between both lead-in wires (E).

5. Disconnect the lead-in wires (E).

6. Remove the screws (F) and remove the carbon brushes (G).

7. Check the carbon brushes (D) for wear. The carbon brushes are worn when:
• The contact with the motor armature is insufficient
• The contact surface is not even
• The stroke is less than 0.12 in (3 mm)
• The thrust spring is broken, etc.

In this cases, replace both motor carbon brushes.

Assembly

8. Assemble the components in the reverse order of disassembly, and note the following:
• after connecting the lead-in wires (E) fasten them with a soldering (D).

A F
G
F
E
B G

P200021
Service Manual – SC450 Recovery System - Battery Version 52

Vacuum System Motor Disassembly/Assembly

1. Remove the recovery water tank.

2. Loosen the fastener (A) and disconnect the hose (B) from the vacuum system motor below.

3. Remove the screws (C) and remove the cover (D).

4. Disconnect the connector (E) and remove the vacuum system motor (F) by lifting it.

Assembly

5. Assemble the components in the reverse order of disassembly.

D
B

C C

F
F

P200022
Service Manual – SC450 Recovery System - Battery Version 53

Specifications
Advance Nilfisk
Descriptions / Model
SC450 20B SC450 53B
Recovery tank capacity 11.9 US gal (45 liters)
Vacuum power 0.44 hp (330 W)
Vacuum water lift (blocked) 43.3 inH2O (1,100 mmH2O)
Service Manual – SC450 Recovery System - Cable Version 54

Recovery System - Cable Version

Functional Description
The water recovery system removes the dirty water The automatic float in the vacuum grid stops vacuum
from the floor and pipes it to a recovery tank. When system motor (M2) from collecting any liquids.
the machine is running, the dirty water on the floor is When the automatic float closes and shuts down the
collected by the squeegee blades and collected through vacuum system, the vacuum system motor noise will
the slots in the same, piped through the vacuum hose increase and the floor will not be dried.
and into the tank by the airflow created by vacuum When the recovery tank is full it can be emptied
motor (M2). The dirty water is piped into the recovery through the drain hose.
tank, while the airflow continues to the vacuum fan.
The vacuum system motor (M2) is supplied by the
switch (SW2).

Wiring Diagram
MAINS PLUG (PL) MAINS FILTER (FL1)

VACUUM SWITCH (SW2)

VACUUM MOTOR (M2)

P200017C
Service Manual – SC450 Recovery System - Cable Version 55

Component Location
• Recovery tank • Recovery water drain hose
• Vacuum grid with automatic shut-off float • Recovery water vacuum hose
• Recovery tank cover • Vacuum system motor (M2)
• Cover gasket

Recovery water
drain hose

Cover gasket

Recovery water
vacuum hose

Recovery tank cover

Vacuum grid with Recovery tank

automatic shut-off
float

Vacuum system
motor (M2)

P200018C
Service Manual – SC450 Recovery System - Cable Version 56

Maintenance and Adjustments

Tank and Vacuum Grid Cleaning

1. Drive the machine to the appointed disposal area.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Discharge the recovery water from the relevant tank.

4. Open the recovery tank cover (A), then clean and wash the cover, the tank (B) and the vacuum grid (C)
with clean water.
If necessary, remove the grid (C) clean it carefully and reinstall it.
If necessary, clean also the solution tank.
Drain the water from the tanks with the relevant drain hoses.

5. Check the recovery tank cover gasket (D) for integrity.

The gasket (D) must be in good shape, as it is necessary for the recovery tank stay sealed.
If necessary replace the gasket (D) by removing it from its housing. When assembling the new gasket,
install its junction (E) in the central rear area as shown in the figure.

6. Check that the seating surface (F) of the gasket (E) is integral and adequate for the gasket itself.

7. Close the recovery tank cover (A).

A F

B
P200019
Service Manual – SC450 Recovery System - Cable Version 57

Troubleshooting
Trouble Possible Causes Remedy

The vacuum system motor does not turn The vacuum system motor carbon brushes are worn Replace
on
The switch (SW2) is broken Replace

The vacuum system motor is faulty Check the amperage.

Check the carbon brushes.

Replace.

The recovery water vacuuming is The vacuum grid with automatic shut-off float is activated Drain the recovery tank
insufficient or there is no vacuuming because the recovery tank is full

The vacuum grid is dirty Clean

The tank cover is not correctly positioned Adjust

The tank cover gasket is not efficient Clean/replace

The vacuum system motor filter is dirty Clean

The vacuum gaskets are damaged or do not match Repair or replace

perfectly

The squeegee vacuum hose is broken Replace

The recovery tank vacuum hose is broken Replace

Service Manual – SC450 Recovery System - Cable Version 58

Removal and Installation

Vacuum System Motor Amperage Check

Warning! This procedure must be performed by qualified personnel only.

1. Check that the squeegee and the vacuum hose are clean and that there is no dirt in their inner parts.

2. Keep the squeegee lifted.

3. Remove the recovery water tank.

Warning! Do not touch uncovered electrical components while performing the following steps.

4. Apply the Amp clamp on the electrical main cable.

5. Turn on the vacuum system and check that the vacuum system motor amperage is 2,0 e 3,0 Amp at 230
Vac.
Turn off the vacuum system.
Remove the Amp clamp (A).
If the amperage is higher, perform the following procedures to detect and correct the abnormal input:
• Check the condition of the vacuum system motor carbon brushes
• Remove the vacuum system motor (see the procedure in the Vacuum System Motor Disassembly/As-
sembly paragraph), and check the condition of all its components.

If the above-mentioned procedures do not produce the correct readings for the vacuum system motor
amperage, the motor must be replaced (see the procedure in the Vacuum System Motor Disassembly/
Assembly paragraph).

Reassemby
6. Assemble the components in the reverse order of disassembly.
Service Manual – SC450 Recovery System - Cable Version 59

Vacuum System Motor Carbon Brush Check/Replacement

Disassembly/Check

1. Remove the vacuum system motor (see the procedure in the Vacuum System Motor Disassembly/
Assembly paragraph).

2. At the workbench, remove the sealing ring (A) from the vacuum system motor (B).

3. Remove the fan cover (C) by disengaging its inner fasteners.

4. With a proper tool, remove the soldering (D) between both lead-in wires (E).

5. Disconnect the lead-in wires (E).

6. Remove the screws (F) and remove the carbon brushes (G).

7. Check the carbon brushes (D) for wear. The carbon brushes are worn when:
• The contact with the motor armature is insufficient
• The contact surface is not even
• The stroke is less than 0.12 in (3 mm)
• The thrust spring is broken, etc.

In this cases, replace both motor carbon brushes.

Assembly

8. Assemble the components in the reverse order of disassembly, and note the following:
• after connecting the lead-in wires (E) fasten them with a soldering (D).

A F
G
F
E
B G

P200021
Service Manual – SC450 Recovery System - Cable Version 60

Vacuum System Motor Disassembly/Assembly

1. Remove the recovery water tank.

2. Loosen the fastener (A) and disconnect the hose (B) from the vacuum system motor below.

3. Remove the screws (C) and remove the cover (D).

4. Disconnect the connector (E) and remove the vacuum system motor (F) by lifting it.

Assembly

5. Assemble the components in the reverse order of disassembly.

D
B

C C

F
F

P200022
Service Manual – SC450 Recovery System - Cable Version 61

Specifications
Nilfisk
Descriptions / Model
SC450 53E
Recovery tank capacity 11.9 US gal (45 liters)
Vacuum power 0.44 hp (550 W, 50-60 Hz)
Vacuum water lift (blocked) 0.44 hp (550 W, 50-60 Hz)
Service Manual – SC450 Scrub System, Disc - Battery Version 62

Scrub System, Disc - Battery Version

Functional Description
The disc brush system can be started by the operator. the brushes after about one minute of continuous
The disc brush turn counter-clockwise. overload. The overload is shown by the three battery
The brush system, when turning, cleans/washes the warning LEDs flashing simultaneously.
floor surface and assist machine forward movement. The overload is detected by monitoring the current
The deck, where brushes suitable for cleaning the flow on the motor. The current is measured by check-
particular type of floor are installed, is the main part ing the voltage drop through the brush fuse (F1). If
of the brush system. The brush deck is fixed and in- the voltage drop is higher than 40 mV, the 3 battery
tegrated in the machine with a support plate. On the LEDs flash simultaneously and, if the overload per-
support plate, there are two handwheels to adjust the sists, the motor stops after a variable delay, depend-
machine straight forward movement and speed. ing on the overload amount.
The brush working pressure is functional to the ma- To start scrubbing again after a brush stop due to
chine designed balance. overload, turn off and then on the machine with the
The brush motor (M1) is supplied by the electromag- brush switch (SW1).
netic switch (ES1) which is driven by the function To work properly, the brush motor needs the follow-
electronic board (EB1) when the switches (SW1) and ing:
(SW3 with SW4) are closed. The circuit is protected • Brush switch (SW1) turned on
by the brush fuse (F1) and by the electronic protection • Push-button (SW3) pressed
system described in the Function Electronic Board • Charged battery (the red LED must not be flash-
Specifications, in the Control System chapter. ing).
The system, once activated, uses the solution coming
form the solution system, to wash the floor.
In case of brush motor overload, a safety system stops

Wiring Diagram

J2.7 - Power supply (+)

FUNCTION ELECTRONIC
BRUSH BOARD (EB1)
SWITCH (SW1)
24V
J1.1 - Switch power supply BRUSH
MOTOR (M1)

J1.8 - Brush system switch

SOLENOID VALVE AND
ELECTRONIC BOARD FUSE (F3)

J1.2 - Brush switch

BRUSH ACTIVATION
PUSH-BUTTONS (SW3) (SW4)
24V
J2.2 - Brush relay power supply BRUSH MOTOR
ELECTROMAGNETIC
SWITCH (ES1)
B-
J2.1 - Relay power supply

BRUSH MOTOR J2.5 - Brush motor current detection (+)

ELECTROMAGNETIC
SWITCH (ES1)
J2.4 - Brush motor current detection (-)
J2.6 - Power supply (-)
BRUSH MOTOR
FUSE (F1)

P2000023
Service Manual – SC450 Scrub System, Disc - Battery Version 63

Component Location
• Disc brush deck • Machine forward speed adjusting handwheel
• Brush motor (M1) • Machine straight forward movement adjusting
• Drive hub handwheel
• Brush electromagnetic switch (ES1)
• Brush fuse (F1)

Brush motor (M1)

Machine straight
forward movement
adjusting handwheel

Machine forward
Disc brush deck speed adjusting
handwheel

Drive hub

Brush electromagnetic
switch (ES1) Fuse (F1)

P2000024
Service Manual – SC450 Scrub System, Disc - Battery Version 64

Maintenance and Adjustments

Brush Cleaning

Warning! It is advisable to wear protective gloves when cleaning the brush because there may
be sharp debris.

1. Drive the machine on a level floor and lift the brush/pad-holder deck. Make sure that the machine
cannot move independently.

2. Check that the control panel switches are turned to “0”.

3. Remove the brush/pad-holder (A) according to the following procedure:

• When the deck is lifted, grab the brush/pad-holder with the hands and turn it first in one direction
(B) and then in the other direction (C) to release it.

4. Clean the brush with water and detergent.

5. Check the brush bristles for integrity and wear; if necessary, replace the brush.

6. Install the brush.

C
Front B
P2000025
Service Manual – SC450 Scrub System, Disc - Battery Version 65

Machine Forward Movement Adjustment

Note: The machine speed and forward movement vary according to the type of floor to be
cleaned and the choice of using the brush or the pad.
If necessary, perform the following procedure.

1. Adjust the machine speed with the handwheel (A) according to the following procedure:
• Turn it counter-clockwise to increase the machine speed.
• Turn it clockwise to decrease the machine speed.

2. If it is difficult to keep the machine moving straight-forwardly because it deviates to the left or to the
right, adjust the knob (B) by turning it clockwise or counter-clockwise.

3. With the machine ready to operate, perform hands-on tests of the machine speed; if necessary, perform
step 2 again.

B A
P2000026
Service Manual – SC450 Scrub System, Disc - Battery Version 66

Troubleshooting
Open Circuit
• The brush fuse (F1) determines an open in the supply circuit of the brush deck motor. This system allows
to prevent the circuits from being damaged under overload conditions.
• The open in the fuse can be caused by the following:
• Short circuit in the brush motor wiring harness; fault in the motor.

Trouble Possible Causes Remedy

The brush does not clean properly The brush is excessively worn Replace

One brush does not turn Activation of motor overload Restart the machine

The motor carbon brushes are worn Replace

The motor is faulty Check the motor amperage/replace

There are ropes or debris restraining the brush rotation Remove and clean

The brush fuse (F1) is open Replace

The motor electromagnetic switch (ES1) is damaged Replace

The brush motor electromagnetic switch wiring harness Repair

is damaged

The brush motor electromagnetic switch wiring harness Repair

is damaged

The wiring harness between function electronic board Repair

(EB1) and brush motor electromagnetic switch (ES1) is
damaged
Service Manual – SC450 Scrub System, Disc - Battery Version 67

Removal and Installation

Brush Motor Amperage Check

Warning! This procedure must be performed by qualified personnel only.

1. Remove the brush.

2. Remove the recovery water tank.

Warning! Do not touch uncovered electrical components while performing the following steps.

3. Apply the Amp clamp (A) on the battery cable (B).

4. Turn on the brush and check that the brush motor amperage is between 2 and 3 A at 24 V.

Stop the brush rotation.

Remove the Amp clamp (A).

If the amperage is higher, perform the following procedures to detect and correct the abnormal input:
• Check that the brush hub is free from foreign materials (ropes, dirt, ...) preventing it from turning.
• Check that the brush fuse (F1) is properly positioned
• Check the condition of the brush motor carbon brushes
• Remove the brush motor (see the procedure in the Brush Motor Disassembly/Assembly paragraph),
and check the condition of all its components.

If the above-mentioned procedures do not produce the correct readings for the brush motor amperage,
the motor must be replaced (see the procedure in the Brush Motor Disassembly/Assembly paragraph).

Reset

5. Assemble the components in the reverse order of disassembly.

B
P2000027
Service Manual – SC450 Scrub System, Disc - Battery Version 68

Brush Motor Carbon Brush Check/Replacement

Disassembly/Check

1. Remove the brush motor (see the procedure in the Brush Motor Disassembly/Assembly paragraph).

2. Fasten the brush motor at the workbench.

Note: Remove one carbon brush at a time, to avoid confusing their positions.

3. Remove the screw (A) of one of the four carbon brush assemblies (B).

4. Remove the carbon brush assembly (B) by disengaging the inner fasteners (C) and (D).

5. If necessary, remove the screw (E) and disconnect the electrical connection (F) from the carbon brush
assembly.

6. Check the carbon brush (G) for wear. The carbon brush is worn when:
• The contact with the motor armature is insufficient
• The contact surface is not even
• The stroke is less than 0.12 in (3 mm)
• The thrust spring is broken, etc.

7. Remove and check the other carbon brush assemblies (B) by performing steps 3 to 6.

8. If necessary, disconnect the electrical connection (F) and remove the carbon brush assemblies to replace
them.

Replace the carbon brushes as an assembly.

Assembly

9. Assemble the components in the reverse order of disassembly, and note the following:

When fastening the electrical connections (F), take care of their insulation from the surrounding parts of
the frame.

G
D

A A

B B B F E C
P2000028
Service Manual – SC450 Scrub System, Disc - Battery Version 69

Brush Deck Disassembly/Assembly

Disassembly

1. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

2. Remove the recovery water tank.

3. Loosen the fastener (A) and disconnect the hose (B) from the vacuum system motor below.

4. Remove the screws (C) and remove the cover (D).

5. On the brush motor (E) disengage the rubber caps (F), then disconnect the electrical connections (G) of
the motor.

F
B
D G
G

C E
C
P2000029
Service Manual – SC450 Scrub System, Disc - Battery Version 70

Brush Deck Disassembly/Assembly (Continues)

6. Remove the plugs (H) on the machine front sides and remove the screws below.

7. Lift the machine front side (I) and keep it lifted.

8. Loosen the screws (J) fastening the solution solenoid valve (K).

9. Move the solenoid valve (K) and disconnect the hose (L) from the solenoid valve by pulling it.

10. Recover the brush deck (M).

Assembly

11. Assemble the components in the reverse order of disassembly.

H
H

J
M L

P2000030
Service Manual – SC450 Scrub System, Disc - Battery Version 71

Brush Motor Disassembly/Assembly

Disassembly

1. Remove the brush.

2. Place the machine on a hoisting system.

3. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

4. Remove the recovery water tank.

5. Loosen the fastener (A) and disconnect the hose (B) from the vacuum system motor below.

6. Remove the screws (C) and remove the cover (D).

7. On the brush motor (E), cut the fastening clamp (F) of the wiring harness (G).

8. Move the rubber caps (H) protecting the electrical connections (I).

9. Remove the nuts and disconnect the electrical connections (I) from the motor (E).

H
B I E
D
F

I G

C C H

P2000031
Service Manual – SC450 Scrub System, Disc - Battery Version 72

Brush Motor Disassembly/Assembly (Continues)

10. Lift the machine with the hoisting system; then let the brush hub (J) to protrude slightly from the edge
of the hoisting system.

11. Remove the screw (K).

12. Remove the brush hub (J); if necessary use a sliding hammer puller (L).

13. Remove the brush motor fastening screws (M).

14. Lower the hoisting system, then remove the brush motor (E).

Assembly

15. Assemble the components in the reverse order of disassembly.

I J

J L

M
M

P2000032
Service Manual – SC450 Scrub System, Disc - Battery Version 73

Specifications
Advance Nilfisk
Descriptions / Model
SC450 20B SC450 53B
Brush diameter 20 in (530 mm)
Brush pressure with full tank and lowered squeegee 66 lb (30 kg)
Brush motor power 0.64 hp (480 W)
Brush rotation speed 154 rpm
Service Manual – SC450 Scrub System, Disc - Cable Version 74

Scrub System, Disc - Cable Version

Functional Description
The disc brush system can be started by the operator. The brush motor (M1) is supplied by the electromag-
The disc brush turn counter-clockwise. netic switch (ES1) which is driven by the fu switches
The brush system, when turning, cleans/washes the (SW1) and (SW3 with SW4).
floor surface and assist machine forward movement. The system, once activated, uses the solution coming
The deck, where brushes suitable for cleaning the form the solution system, to wash the floor.
particular type of floor are installed, is the main part
of the brush system. The brush deck is fixed and in- To work properly, the brush motor needs the follow-
tegrated in the machine with a support plate. On the ing:
support plate, there are two handwheels to adjust the • Brush switch (SW1) turned on
machine straight forward movement and speed. • Push-buttons (SW3) pressed
The brush working pressure is functional to the ma-
chine designed balance.

Wiring Diagram
MAINS PLUG (PL) MAINS FILTER (FL1)

BRUSH SWITCH (SW1)

BRUSH ACTIVATION
PUSH-BUTTONS (SW3) (SW4)

BRUSH MOTOR RELAY (ES1)

DISC BRUSH MOTOR (M1)

P2000023C
Service Manual – SC450 Scrub System, Disc - Cable Version 75

Component Location
• Disc brush deck • Machine forward speed adjusting handwheel
• Brush motor (M1) • Machine straight forward movement adjusting
• Drive hub handwheel
• Brush electromagnetic switch (ES1)

Brush motor (M1)

Machine straight
forward movement
adjusting handwheel
Machine forward
Disc brush deck speed adjusting
handwheel

Drive hub

brush motor
relay (ES1)

P2000024
Service Manual – SC450 Scrub System, Disc - Cable Version 76

Maintenance and Adjustments

Brush Cleaning

Warning! It is advisable to wear protective gloves when cleaning the brush because there may
be sharp debris.

1. Drive the machine on a level floor and lift the brush/pad-holder deck. Make sure that the machine
cannot move independently.

2. Check that the control panel switches are turned to “0”.

3. Remove the brush/pad-holder (A) according to the following procedure:

• When the deck is lifted, grab the brush/pad-holder with the hands and turn it first in one direction
(B) and then in the other direction (C) to release it.

4. Clean the brush with water and detergent.

5. Check the brush bristles for integrity and wear; if necessary, replace the brush.

6. Install the brush.

C
Front B
P2000025
Service Manual – SC450 Scrub System, Disc - Cable Version 77

Machine Forward Movement Adjustment

Note: The machine speed and forward movement vary according to the type of floor to be
cleaned and the choice of using the brush or the pad.
If necessary, perform the following procedure.

1. Adjust the machine speed with the handwheel (A) according to the following procedure:
• Turn it counter-clockwise to increase the machine speed.
• Turn it clockwise to decrease the machine speed.

2. If it is difficult to keep the machine moving straight-forwardly because it deviates to the left or to the
right, adjust the knob (B) by turning it clockwise or counter-clockwise.

3. With the machine ready to operate, perform hands-on tests of the machine speed; if necessary, perform
step 2 again.

B A
P2000026
Service Manual – SC450 Scrub System, Disc - Cable Version 78

Troubleshooting
Trouble Possible Causes Remedy

The brush does not clean properly The brush is excessively worn Replace

One brush does not turn The motor carbon brushes are worn Replace

The motor is faulty Check the motor amperage/replace

There are ropes or debris restraining the brush rotation Remove and clean

The motor electromagnetic switch (ES1) is damaged Replace

The brush motor electromagnetic switch wiring harness Repair

is damaged

The brush motor electromagnetic switch wiring harness Repair

is damaged
Service Manual – SC450 Scrub System, Disc - Cable Version 79

Removal and Installation

Brush Motor Amperage Check

Warning! This procedure must be performed by qualified personnel only.

1. Remove the brush.

2. Remove the recovery water tank.

Warning! Do not touch uncovered electrical components while performing the following steps.

3. Apply the Amp clamp (A) on the battery cable (B).

4. Turn on the brush and check that the brush motor amperage is between 2 and 4 Amp at 230 Vac.

Stop the brush rotation.

Remove the Amp clamp (A).

If the amperage is higher, pes to detect and correct the abnormal input:
• Check that the brush hub is free from foreign materials (ropes, dirt, ...) preventing it from turning.
• Remove the brush motor (see the procedure in the Brush Motor Disassembly/Assembly paragraph),
and check the condition of all its components.

If the above-mentioned procedures do not produce the correct readings for the brush motor amperage,
the motor must be replaced (see the procedure in the Brush Motor Disassembly/Assembly paragraph).

Reset

5. Assemble the components in the reverse order of disassembly.

Service Manual – SC450 Scrub System, Disc - Cable Version 80

Brush Deck Motor - Capacitor Wiring Diagram (230V)

Internal wiring connections

(A) (B)
Starting Working
Capacitor Capacitor
65 / 70µF 30µF

(A) (B) Internal

Starting Working
Capacitor Capacitor
65 / 70µF 30µF V2 W1

Internal

U2 V1

Internal

Internal
W2 U1
Internal

Power cable
Service Manual – SC450 Scrub System, Disc - Cable Version 81

Specifications
Nilfisk
Descriptions / Model
SC450 53E
Brush diameter 20 in (530 mm)
Brush pressure with full tank and lowered squeegee 88 lb (40 kg)
Brush motor power 0.64 hp (1.100 W, 50-60 Hz)
Brush rotation speed 150 rpm
Service Manual – SC450 Solution System - Battery Version 82

Solution System - Battery Version

Functional Description
The solution system supplies the detergent to the The solenoid valve (EV1) is supplied by the function
brushes when cleaning the floor. The solution tank is electronic board (EB1) when the switches (SW1) and
also the main machine body. The detergent quantity (SW3 with SW4) are closed. The circuit is protected
is adjusted by the operator with the lever under the by the control/solenoid fuse (F3) on the function elec-
solution tank, on the left rear side. The solution flows tronic board (EB1). The solution flow is regulated by
from the tank to the tap, through the filter and sole- the manual solution flow control lever.
noid valve (EV1) and then to the brush deck.

Wiring Diagram

J2.7 - Power supply (+)

SOLENOID VALVE AND
ELECTRONIC BOARD FUSE (F3)
BRUSH
SWITCH (SW1)
24V
J1.1 - Switch power supply

J1.8 - Brush system switch

FUNCTION ELECTRONIC
BOARD (EB1)

J1.2 - Brush switch

24V
BRUSH ACTIVATION
PUSH-BUTTONS (SW3) (SW4) J3.1 - Solenoid valve (+)

B-
J3.2 - Solenoid valve (-)
SOLENOID VALVE
(EV1)
J2.6 - Power supply (-)

P200033
Service Manual – SC450 Solution System - Battery Version 83

Component Location
• Solution tank • Solenoid valve (EV1)
• Solution flow control lever • Solution drain and level check hose
• Solution filter

Solution
tank

Solution drain
and level check
hose

Solenoid valve (EV1) Solution Solution flow

filter control lever
P200034
Service Manual – SC450 Solution System - Battery Version 84

Maintenance and Adjustments

Solution Filter Cleaning

1. Drain the solution tank.

2. Drive the machine on a level floor. Make sure that the machine cannot move independently.

3. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

4. On the machine lower side, in front of the left centre wheel, unscrew the transparent cover (A) with the
gasket (B), then remove the filter strainer (C). Clean and install them on the support (D); install the
gasket (B) and the filter strainer (C) properly on the cover (A) and on the support (D).

5. Connect the battery connector (red).

D
C
B
A
P200035
Service Manual – SC450 Solution System - Battery Version 85

Troubleshooting
Trouble Possible Causes Remedy

Small amount of solution or no solution The tank filter (optional) is clogged/dirty Clean the filter
reaches the brush
The solution filter is clogged/dirty Clean

The solenoid valve (EV1) is faulty or the electrical Replace the solenoid valve or
connection is open repair the electrical connection

There is dust/debris in the tank or in the detergent hoses, Clean the tank/hoses
obstructing the solution flow

There is an open in the control/solenoid fuse (F3) Replace

The solution reaches the brush also There is dirt or calcium deposit on the solenoid valve Clean the solenoid valve inner
when the machine is off gaskets (EV1) gaskets

The solenoid valve (EV1) is broken Replace the solenoid valve

Specifications
Advance Nilfisk
Descriptions / Model
SC450 20B SC450 53B
Solution tank capacity 10.5 US gal (40 liters)
Min/max solution flow 0.10÷0.42 gpm (0.4÷1.6 liters/min)
Service Manual – SC450 Solution System - Cable Version 86

Solution System - Cable Version

Functional Description
The solution system supplies the detergent to the The solenoid valve (EV1) is supplied by the brush
brushes when cleaning the floor. The solution tank is motor relay (ES) when the switches (SW1) and (SW3
also the main machine body. The detergent quantity with SW4) are closed. The solution flow is regulated
is adjusted by the operator with the lever under the by the manual solution flow control lever.
solution tank, on the left rear side. The solution flows
from the tank to the tap, through the filter and sole-
noid valve (EV1) and then to the brush deck.

Wiring Diagram
MAINS PLUG (PL) MAINS FILTER (FL1)

BRUSH SWITCH (SW1)

BRUSH ACTIVATION
PUSH-BUTTONS (SW3) (SW4)

BRUSH MOTOR RELAY (ES1)

SOLENOID VALVE (EV1)

P200033C
Service Manual – SC450 Solution System - Cable Version 87

Component Location
• Solution tank • Solenoid valve (EV1)
• Solution flow control lever • Solution drain and level check hose
• Solution filter

Solution
tank

Solution drain
and level check
hose

Solenoid valve (EV1) Solution Solution flow

filter control lever
P200034C
Service Manual – SC450 Solution System - Cable Version 88

Maintenance and Adjustments

Solution Filter Cleaning

1. Drain the solution tank.

2. Drive the machine on a level floor. Make sure that the machine cannot move independently.

3. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

4. On the machine lower side, in front of the left centre wheel, unscrew the transparent cover (A) with the
gasket (B), then remove the filter strainer (C). Clean and install them on the support (D); install the
gasket (B) and the filter strainer (C) properly on the cover (A) and on the support (D).

5. Connect the battery connector (red).

D
C
B
A
P200035
Service Manual – SC450 Solution System - Cable Version 89

Troubleshooting
Trouble Possible Causes Remedy

Small amount of solution or no solution The tank filter (optional) is clogged/dirty Clean the filter
reaches the brush
The solution filter is clogged/dirty Clean

The solenoid valve (EV1) is faulty or the electrical Replace the solenoid valve or
connection is open repair the electrical connection

There is dust/debris in the tank or in the detergent hoses, Clean the tank/hoses
obstructing the solution flow

The solution reaches the brush also There is dirt or calcium deposit on the solenoid valve Clean the solenoid valve inner
when the machine is off gaskets (EV1) gaskets

The solenoid valve (EV1) is broken Replace the solenoid valve

Specifications
Nilfisk
Descriptions / Model
SC450 53E
Solution tank capacity 10.5 US gal (40 liters)
Min/max solution flow 0.105/0.422 gpm (0.4/1.6 liters/min)
Service Manual – SC450 Squeegee System 90

Squeegee System

Functional Description
The squeegee system cleans the liquid off the floor, The angle of the squeegee and the correct adherence
which is then collected by the recovery system. of the blades on the floor can be adjusted with a knob.
The squeegee is mounted on castors, the pressure of The front blade has openings on the edges to convey
the tires on the floor is caused by the spring load on and collect the water towards the centre of the squee-
the system. gee. The design and the central duct make it easy for
The squeegee is fastened to the machine by two wing the squeegee to clear the water. The rear blade edge is
nuts in the squeegee support slots. In case of fixed smooth, to collect the water and dry the floor.
obstacles, the quick-fit system allows for squeegee im- All 4 functional edges of each blade can be used before
mediate removal. it needs replacing.
The squeegee support is hinged to the machine by The squeegee is lifted and lowered by a cable which is
means of a bracket which allows the squeegee to turn manually controlled by the operator with a knob.
sideways.
Service Manual – SC450 Squeegee System 91

Component Location
• Squeegee • Squeegee adjustment
• Squeegee blades • Squeegee lifting/lowering lever
• Squeegee holder • Squeegee lifting/lowering cable
• Mounting handwheels

Squeegee
lifting/lowering lever
Squeegee
holder
Squeegee
lifting/lowering cable

Squeegee adjustment

Squeegee
Mounting handwheels

Squeegee blades
P200036
Service Manual – SC450 Squeegee System 92

Maintenance and Adjustments

Squeegee Cleaning

Warning! It is advisable to wear protective gloves when cleaning the squeegee because there
may be sharp debris.

1. Drive the machine on a level floor. Make sure that the machine cannot move independently.

2. Check that the control panel switches are turned to “0”.

3. Lower the squeegee with the lever.

4. Disconnect the vacuum hose (A) from the squeegee (B).

5. Loosen the handwheels (C) and remove the squeegee (B).

6. Wash and clean the squeegee (B). In particular, clean the compartments (D) and the vacuum hole (E)
from dirt and debris.

7. Check the front blade (F) and the rear blade (G) for integrity, cuts and tears; if necessary replace them
(see the procedure in the following paragraph).

8. Assemble the components in the reverse order of disassembly, and note the following:

9. If necessary, use the handwheel (H) to adjust the squeegee balance.

C
H C B

G
F
D
E

F G D

E
B
P200037
Service Manual – SC450 Squeegee System 93

Squeegee Blade Check and Replacement

1. Disassemble and clean the squeegee.

2. Check that the edge (A) of the front blade (B) and the edge (C) of the rear blade (D) lay down on the
same level, along their length; otherwise adjust their height according to the following procedure:
• Open the lever (E) and disengage the fasteners (F), then adjust the rear blade (D); after adjusting
engage the fasteners (F) and close the lever (E).
• Loosen the handwheels (G) and adjust the front blade (B); after adjusting tighten the handwheels (G).

3. Check that the front blade (C) and the rear blade (D) are integral and free from cuts and lacerations;
if necessary replace them. Also check the front corner (H) of the rear blade (D) for wear; if it is worn,
overturn the blade to replace the worn corner with the other one (I), if it is integral. If the other corner is
worn too, replace the blade.

4. Assemble the squeegee.

G
D F
B

G
B D

H E
C I
A
F
P200038
Service Manual – SC450 Squeegee System 94

Troubleshooting
Trouble Possible Causes Remedy

The recovery water vacuuming is The squeegee or the vacuum hose is clogged or Clean or repair/replace
insufficient or there is no vacuuming damaged

There is debris under the blade Remove

The squeegee blade edges are torn or worn Replace

The squeegee springs are not efficient Replace

The squeegee is not balanced Adjust with the relevant handwheel

Service Manual – SC450 Squeegee System 95

Removal and Installation

Squeegee Spring Disassembly/Assembly

Disassembly

1. Drive the machine to the appointed disposal area, and empty the recovery tank and the solution tank.

2. Check that the control panel switches are turned to “0”. Disconnect the battery connector (red).

3. Remove the recovery tank.

4. Remove the batteries.

5. Remove the squeegee (as shown in Squeegee Cleaning paragraph).

6. Remove the brush (as shown in Brush Cleaning paragraph).

7. With the help of an assistant, place the machine on a hoisting system (A) (or on a floor with a suitable
step), overturned as shown in the figure; lay the machine front and central side (B) on the hoisting
system (A) and let the rear side (C) free.

8. Remove the screw with the nut (D) and release the squeegee lifting cable (E).

E
B

C A
P200039
Service Manual – SC450 Squeegee System 96

Squeegee Spring Disassembly/Assembly (Continues)

9. Disconnect the solution valve (F), by pulling it.
10. Open the clamps (G) and move aside the hose (H).
11. Disengage the squeegee springs (I) from the bracket (J).
12. Release the retaining rings (K) and recover the springs (L) and the washers (M).
13. Remove the right and left wheels (N) and (P).
14. Remove the other components (Q); remove the wheel shaft (T) from its housing by tapping it with a
plastic mallet (S).
15. Retrieve the squeegee springs (R).

Assembly
16. Assemble the components in the reverse order of disassembly.

T
J

T
F T
H
G

K L M N R T R P M L K

P200040
Service Manual – SC450 Squeegee System 97

Specifications
Nilfisk
Advance
Descriptions / Model SC450 53B
SC450 20B
SC450 53E
Squeegee width 30 in (760 mm)
Service Manual – SC450 Wheel System, Non-Traction 98

Wheel System, Non-Traction

Component Location
• Front wheels on fixed axle
• Rear parking wheel
• Machine in parking position

Front wheels
on fixed axle
Rear parking wheel

Machine
in parking
position

P200041
Service Manual – SC450 Wheel System, Non-Traction 99

Specifications
Nilfisk
Advance
Descriptions / Model SC450 53B
SC450 20B
SC450 53E
Diameter of wheels on fixed axle 10 in (254 mm)
Wheel pressure on the floor 710 psi (4.9 N/mm2)