Installation, Operation and Maintenance Instructions

1200°C Large Chamber Furnace - LCF Model: 560 Litres

No Controller

LCF 12/560 + No Controller

MEN-LCF12560-005_NOCTRL (29-10-2021)
Contents
This manual is for guidance on the use of the Carbolite Gero product specified on the
front cover. This manual should be read thoroughly before unpacking and using the
furnace or oven. The model details and serial number are shown on the back of this
manual. Use the product for the purpose for which it is intended.

1.0 Symbols and Warnings 4

1.1 Switches and Lights 4
1.2 General Warnings 4
1.3 Prerequisites to Use 5

2.0 Installation 6
2.1 Unpacking & Handling 6
2.2 Siting and Setting Up 6
2.3 Hearth 7
2.4 Chimney 7
2.5 Electrical Connections 8
2.6 Voltage and Power Limit 9

3.0 Temperature Controller 10

4.0 Operation 11
4.1 Operating Cycle 11
4.2 General Operating Notes 11
4.3 Use of Probes and Metal Sheathed Thermocouples 12
4.4 Atmospheres 12
4.5 Operator Safety 12
4.6 Power Adjustment 13

5.0 Maintenance 14
5.1 General Maintenance 14
5.2 Maintenance Schedule 14
5.2.1 Cleaning 16
5.3 Safety Switch 16
5.4 Calibration 16
5.5 After-Sales Service 17
5.6 Recommended Spare Parts and Spare Parts Kit 17

6.0 Repairs and Replacements 18

6.1 Safety Warning - Disconnection from Power Supply 18
6.2 Safety Warning - Refractory Fibre Insulation 18
6.3 Temperature Controller Replacement 18
6.4 Solid-State Relay Replacement 19

2
 6.5 Thermocouple Replacement 19
6.6 Element Installation and Replacement 19
6.6.1 Top Element Replacement 1200 °C Models 20
6.6.2 Bottom Element Replacement 1200 °C Models 21
6.7 Fuse Replacement 22

7.0 Fault Analysis 23

A. Furnace Does Not Heat Up 23
B. Product Overheats 24

8.0 Wiring Diagrams 25

8.1 WA-33-30 25
8.2 WA-33-31 26
8.3 WA-U3-30 27
8.4 WA-U3-31 29

9.0 Fuses and Power Settings 31

9.1 Fuses 31
9.2 Power Settings 31

10.0 Specifications 32
10.1 Environment 32

3
 1.0 Symbols and Warnings

1.1 Switches and Lights

Instrument switch: when the instrument switch is operated the

temperature control circuit is energised.

Heat light: the adjacent light glows or flashes to indicate that

power is being supplied to the elements.

1.2 General Warnings

DANGER – Electric shock. Read any warning printed next to this

symbol.
WARNING: Risk of fatal injury.

DANGER – Hot surface. Read any warning printed next to this

symbol.
WARNING: All surfaces of a product may be hot.

DANGER – Read any warning printed next to this symbol.

Caution – Double Pole/Neutral Fusing

4
1.3 Prerequisites to Use
Prior to the commissioning and use of this product, all personnel involved in its
installation, operation and maintenance must be deemed competent and have:
l Read and understood the information contained within this manual
l Received the relevant training with regard to safety and operation of the product
l Been provided with the appropriate PPE (Personal Protective Equipment) required
for the safe operation of this product

Note: The customer is responsible for ensuring that all of the above conditions are
satisfied before the product is commissioned for use.

Note: Unless otherwise specified, the customer is responsible for the

installation of this product and the safe connection of any additional
equipment and gas or liquid supply lines.

5
 2.0 Installation

2.1 Unpacking & Handling

When unpacking or moving the product, always lift by its base; do not use the door or
any other projecting cover or component to support the equipment when moving it. Use
a fork lift or pallet truck to move the product; position the product on a level surface
and use an adequate number of personnel to safely move the product into position.
Carefully remove any packing material from inside and around the product before use.
Avoid damaging the surrounding insulation when removing packing materials.

NOTE: This product contains Refractory Ceramic Fibre (also known

as Alumino Silicate Wool - ASW). For precautions and advice on
handling this material see section 6.2.

2.2 Siting and Setting Up

Place the product on a level surface in a well ventilated area.
Site away from other sources of heat and on a non-flammable surface that is resistant
to accidental spillage or hot materials.
The surface on which the equipment is mounted should be stable and not subject to
movement or vibrations.
The height of the mounting surface is important to avoid operator strain when loading
and unloading samples.
Unless otherwise stated elsewhere in this manual, ensure that there is at least 150
mm of free space around the back and sides of the product. Clear space is required
above the product to dissipate heat.

6
Depending on the application of the product, it may be appropriate to position it under
an extraction hood. Ensure the extraction hood is switched on during use.
Ensure that the product is placed in such a way that it can be quickly switched off or
disconnected from the electrical supply.

Under no circumstances should any objects be placed on top of the

product. Always ensure that any vents on the top of the product are clear
of any obstruction. Always ensure all cooling vents and cooling fans (if
fitted) are clear of any obstruction.

2.3 Hearth
The hearth and chamber are supported during transport by packing foam. Remove and
dispose of this packaging.

2.4 Chimney
The chimney is a length of tubing. If it is supplied unfitted, then fit it through the hole
in the top of the case.
If the product is to be used to heat substances that emit fumes, a fume extraction duct
of approximately 75 mm - 150 mm inlet diameter may be placed directly above the
chimney outlet.
Do not make a sealed connection to the product chimney as this causes excessive
airflow through the chamber and results in poor temperature uniformity.

7
 Key

A Duct (75mm-150mm diameter)

B Ambient air is drawn into duct

C Chimney

D 25mm vertical gap between chimney and duct

2.5 Electrical Connections

Connection by a qualified electrician is recommended.

The model covered in this manual has three internal circuits and is normally supplied
for connection to a three phase power supply. This may be either star or delta, but a
product must only be connected to the type and voltage of supply for which it was
made. If the product is ordered for a single phase supply, this may be Live to Neutral
reversible or non-reversible, or Live to Live.
Check the product rating label before connection. The supply voltage should agree with
the voltage on the label and the supply capacity should be sufficient for the current on
the label.
The supply should be fused at the next size equal to, or higher than the current on the
label. This manual contains a table of the most common fuse ratings.
When the mains cable is factory fitted, internal fuses are also fitted. It is essential that
the operator ensures that the product is correctly fused.
Products with a factory fitted supply cable are designed to be wired directly to an
isolator or fitted with a line plug.
Products without a factory fitted supply cable require a permanent connection to a
fused and isolated supply. The product's electrical access panel should be temporarily
removed, and connections made to the internal terminals.
When connecting the product to the power supply, the plug or isolating switch should
be accessible, easy to remove, and within reach of the operator.

8
The supply MUST incorporate an earth (ground).
Electrical Connection Details:
Supply Types
Supply Terminal Label Cable Colour Reversible or Live-
Live - Neutral
Live
to either power
conductor
1-phase L1 Brown to live
(For USA 200-240V,
connect L1)
to the other power
conductor
N / L2 Blue to neutral
(For USA 200-240V,
connect L2)
to earth
PE Green/ Yellow to earth (ground)
(ground)

2- or
L1 Black to phase 1
3-phase

L2 Black to phase 2

L3 Black to phase 3 (except 2-phase)

N Light Blue to neutral (except delta)
PE Green/ Yellow to earth (ground)

2.6 Voltage and Power Limit

When first starting up the product, check the setting of the OP.Hi
parameter (see the controller instructions) and compare it with the
data in section 9.0 towards the back of this manual.

If the power limit setting is incorrect for the voltage of the electrical supply, change it.
This must be done immediately if the setting of OP.Hi is higher than it should be.

9
 3.0 Temperature Controller
If this product is fitted with a temperature controller, instructions are provided
separately.

10
4.0 Operation

4.1 Operating Cycle

This product is fitted with an instrument switch which cuts off power to the control
circuit.
Connect the product to the electrical supply.
Turn on the instrument switch to activate the temperature controllers. The controllers
illuminate and go through a short test cycle.
Over-Temperature option only. If the digital over-temperature option has not yet
been set as required, set and activate it according to the over-temperature controller
instructions.
The product will heat up according to the controller setpoint or program, unless a time
switch is fitted and switched off.
As the product heats up, the heat light glows steadily at first and then flashes as the
product approaches the desired temperature. For more information on temperature
control see the controller instructions.
Over-Temperature option only. If the over-temperature circuit has tripped, an
indicator on the over-temperature controller flashes and the heating elements are
isolated. Find and correct the cause before resetting the over-temperature controller
according to the instructions supplied.
To turn the product off, set the instrument switch to its off position. The controller
display will go blank. If the product is to be left unattended, isolate it from the
electrical supply.

4.2 General Operating Notes

Heating element life is shortened by overheating. Do not leave the

product at high temperature when it is not required. The maximum
temperature is shown on the product rating label and in section 10.0
towards the back of this manual.

When heating large objects, in particular poor conductors, avoid shielding the
thermocouple from the heating elements. The thermocouple is intended to sense the
temperature near the heating elements. However, if a large object is placed in the
chamber it may record the average temperature of the object and the elements, this
can lead to overheating of the elements. Allow large objects to gain heat at a lower
temperature and then reset the controller to a temperature close to the desired
maximum, or heat using a slowly controlled ramp rate. For more information refer to
the controller instructions.
When heating materials that produce smoke or fumes, the chimney must be correctly
fitted and unobstructed. If not, soot will accumulate in the chamber and could possibly
cause an electrical breakdown of the heating element. If the furnace is used to heat
materials that emit smoke or fumes, regularly heat it up to maximum temperature for
one hour with the chamber empty to burn away the soot.

11
Materials such as case hardening compounds and other reactive salts may penetrate
the furnace chamber lining and attack the wire elements, causing premature failure.
Use of a hearth tile may be advisable: please consult the Carbolite Gero technical
department.

4.3 Use of Probes and Metal Sheathed Thermocouples

Any metal object used to probe into the product chamber while the
product is connected to the electrical supply must be earthed. This
applies in particular to metal sheathed thermocouples, where the
sheaths must be earthed. The refractory material of the chamber
lining becomes partly conductive at high temperatures and the
electric potential inside the chamber can be at any value between
zero and the supply voltage. Unearthed probes can cause serious
electric shock.

4.4 Atmospheres
When an optional gas inlet is fitted, there is a label near the inlet saying "INERT GAS
ONLY". In practice, inert or oxidising gases may be used, but not combustible or toxic
gases.

The chamber is not gas tight, the gas usage may be high and the chamber is always
likely to contain some air. Residual oxygen of approximately 1% to 2% is to be
expected.

4.5 Operator Safety

This product incorporates a safety switch which interrupts the heating

element circuit when the furnace is opened. This prevents the
operator touching a live heating element and also prevents the
product from heating up if the furnace is left open. The operation of
this switch should be checked periodically.

Depending on use, the surfaces in the working chamber and the

chamber load may still be very hot after the appliance is switched off.
Touching these surfaces may cause burns. Use suitable personal
protective equipment or wait until the appliance cools down to
ambient temperature.

Before removing a hot object from the product, make sure there is a safe place to put it
down. If necessary use tongs, face masks and heat resistant gloves. Heat resistant
clothing and face protection can guard against the effects of radiated heat when the
furnace is open.

12
When the product is opened during operation there is considerable radiated heat. Do
not keep any flammable objects near the product, nor objects which could be damaged
by radiated heat.

4.6 Power Adjustment

The product control system incorporates electronic power limiting. Depending on the
model and the destination country the power limit maybe set to 100% or a lower
figure. Where appropriate the power limit parameter OP.Hi is accessible to the
operator, but it should not generally be altered.
See section 9.0 for details of the power limit settings. DO NOT adjust the power to a
level higher than the design level states; this may cause a fuse to blow and could
damage the heating elements.
The power limit may be set to a lower limit if the product is to be used at a low
temperature only: this may give better control stability. It may be set to zero to permit
demonstration of the controls without the heating elements taking power; to resume
heating reset it to its standard value.

13
 5.0 Maintenance

5.1 General Maintenance

Preventive rather than reactive maintenance is recommended. The type and frequency
depends on the product use; the following are recommended.

5.2 Maintenance Schedule

CUSTOMER
QUALIFIED PERSONNEL

DANGER! ELECTRIC SHOCK. Risk of fatal injury. Only electrically

qualified personnel should attempt these maintenance procedures.

Frequency
Maintenance
Method Bi-
Procedure Daily Weekly Monthly Annually
Annually

Safety

Set a safe temperature above ambient, and

Safety Switch Function open the door to see if the heater light goes
out

Safety Switch Function

Electrical measurement

Set an over-temperature setpoint lower than

Over-Temperature Safety
the displayed temperature and check for an
Circuit
over-temperature alarm as detailed in this
(if fitted)
manual

Over-Temperature Safety
Circuit
(if fitted) Electrical measurement

Ensure the door moves up and down

smoothly and that the door stays up under
Door Mechanism
its own weight. Grease the door-guides with
high temperature grease if necessary

Visual inspection, checking the seal and

Door Insulation
whether it is free of damage

Door Insulation Replacement where necessary

Chimney / Extraction Check and clean if necessary

Electrical Safety
Visual check of external cables and plugs
(external)

Physically check all connections and cleaning

Electrical Safety (internal)
of the power plate area

Function

14
 Tested using certified equipment, frequency
Temperature Calibration
dependent on the standard required

Check that all functions are working nor-

Operational Check
mally

Thorough inspection and report incor-

Operational Check
porating a test of all functions

Performance

Element Circuit
Electrical measurement

Measure the current drawn on each phase /

Power Consumption
circuit

Hearth Visual check for fit and damage

Cooling Fans (if fitted) Check whether the cooling fans are working

15
 5.2.1 Cleaning
Soot deposits may form inside the furnace, depending on the process. At appropriate
intervals remove these by heating as indicated in the General Operation Notes.

The product's outer surface may be cleaned with a damp cloth. Do

not allow water to enter the interior of the case or chamber. Do not
clean with organic solvents.

5.3 Safety Switch

When correctly functioning, the safety switch will isolate all live conductors (live and
neutral connections) within the heating element circuit(s) when the product door is
opened. The safety switch should be checked regularly to ensure that this occurs.

The safety switch should not fail under normal working conditions, however rough
handling, exposure to corrosive materials/ environments, or exceptionally frequent use,
could compromise the safety system.

Weekly check:
The following check can be carried out by a general operator:
l On the temperature controller, set a safe temperature above ambient. The heater
lights should illuminate.
l Open the door and check the heater lights. They should no longer be illuminated.

If the heater lights remain illuminated when the door is open, discontinue use and
contact Carbolite Gero Service.

Annual check:
The following checks should be carried out by a qualified electrician, as specified in the
"Maintenance Schedule" section of this manual:
l Remove the element access panel and take a voltage measurement from the heat-
ing element terminals. Do not attempt to take a reading from the heating element
itself as surface oxidation will give an unreliable contact.
l Ensure that power to the heating elements is switched off when the door is opened.

Contact Carbolite Gero Service and discontinue use of the product if it is found that the
heating elements are not fully isolated during these checks.

5.4 Calibration
After prolonged use, the controller and/or thermocouple may require recalibration. This
is important for processes that require accurate temperature readings or for those that

16
use the product close to its maximum temperature. A quick check using an
independent thermocouple and temperature indicator should be made from time to
time to determine whether full calibration is required. Carbolite Gero can supply these
items.
Depending on the controller fitted, the controller instructions may contain calibration
instructions.

5.5 After-Sales Service

Carbolite Gero Service has a team of Service Engineers who can offer repair, calibration
and preventive maintenance of furnace and oven products both at the Carbolite Gero
factory and at customers’ premises throughout the world. A telephone call or email
often enables a fault to be diagnosed and the necessary parts to be despatched.
In all correspondence please quote the serial number and model type given on the
rating label of the product. The serial number and model type are also given on the
back of this manual when supplied with the product.
Carbolite Gero Service and Carbolite Gero contact information can be found on the
back page of this manual.

5.6 Recommended Spare Parts and Spare Parts Kit

Carbolite Gero can supply individual spare parts or a kit of the items most likely to be
required. Ordering a kit in advance can save time in the event of a breakdown.
Each kit consists of one thermocouple, one sheath, one solid state relay and set of
elements.
When ordering spare parts please quote the model details as requested above.

17
 6.0 Repairs and Replacements

6.1 Safety Warning - Disconnection from Power Supply

Immediately switch the product off in the event of unforeseen

circumstances (e.g. large amount of smoke). Allow the product to
return to room temperature before inspection.
Always ensure that the product is disconnected from the electrical
supply before repair work is carried out.
Caution: Double pole/neutral fusing may be used in this product.

6.2 Safety Warning - Refractory Fibre Insulation

Insulation made from High Temperature Insulation Wool

Refractory Ceramic Fibre, better known as (Alumina silicate
wool - ASW).

This product contains alumino silicate wool products in its thermal insulation. These
materials may be in the form of blanket or felt, formed board or shapes, slab or loose
fill wool.
Typical use does not result in any significant level of airborne dust from these
materials, but much higher levels may be encountered during maintenance or repair.
Whilst there is no evidence of any long term health hazards, it is strongly
recommended that safety precautions are taken whenever the materials are handled.
Exposure to fibre dust may cause respiratory disease.
When handling the material, always use approved respiratory protection
equipment (RPE-eg. FFP3), eye protection, gloves and long sleeved clothing.
Avoid breaking up waste material. Dispose of waste in sealed containers.
After handling, rinse exposed skin with water before washing gently with
soap (not detergent). Wash work clothing separately.
Before commencing any major repairs it is recommended to make reference to the
European Association representing the High Temperature Insulation Wool industry
(www.ecfia.eu).
Further information can be provided on request. Alternatively, Carbolite Gero Service
can quote for any repairs to be carried out either on site or at the Carbolite Gero
factory.

6.3 Temperature Controller Replacement

Refer to the controller instructions for more information on how to replace the
temperature controller.

18
6.4 Solid-State Relay Replacement

Disconnect the product from the power supply and remove the
appropriate cover as given above.

1. Make a note of the wire connections to the solid state relay, then disconnect them.
2. Remove the solid state relay from the base panel or aluminium plate.
3. Replace and reconnect the solid state relay ensuring that the bottom of it has
good thermal contact with the base panel or aluminium plate.
4. Replace the access panel.

6.5 Thermocouple Replacement

Disconnect the product from the power supply. Remove the appropriate
panel to gain access to the thermocouple connections. Make a note of the
thermocouple connections.
Thermocouple cable colour codings are:
Thermocouple leg Colour
positive (type R) orange
negative white
Disconnect the thermocouple from its terminal block and withdraw the thermocouple
from its sheath by bending the metal tag or releasing the screw to release. It is also
advisable to remove the sheath and shake out any broken pieces of thermocouple.
Re-assemble with a new thermocouple, observing the colour coding, ensuring that the
thermocouple is not twisted as it is being inserted and that the metal tag is bent back
to grip the sheath.
Refit the element access panel.

6.6 Element Installation and Replacement

WARNING: Switch off at the instrument control switch and

isolate the furnace from the electrical supply before starting
work.

See section 7.2 - wearing a face mask is recommended.

This operation requires two people and the furnace should be cooled down to room
temperature.
If the furnace is used for application where temperature uniformity is critical as in an
AMS2750E aerospace heat treatment applications then the uniformity of the furnace
will have to be retested once new elements have been fitted.

19
For all elements the heat output may decrease with age. When the furnace was new the
temperature controller may have been set up with a limit on the maximum power
output setting 0P.Hi typically 90%. As the elements aged this may have been adjusted
upwards to compensate for loss of heating. When a set of new elements has been fitted
the maximum power output needs checking to make sure it as per the new furnace
condition. Please contact Carbolite Gero for this figure. See the controller manual to
access and change this setting.
If only a few elements are replaced and the power limit has been increased and left at
this higher figure then the new elements could run hotter and this will shorten their life.
For this reason it is recommended that elements are replaced as full sets.
6.6.1 Top Element Replacement 1200 °C Models
The furnace typically has 15 wire wound elements wound around a ceramic tube.
Remove the side panels. Remove the chimney, the top panel and the top cover of the of
the furnace chamber to which the top insulation blanket is rigidly fixed. It will be
possible to view the elements from above.
Generally elements will be replaced as sets. Make a note of the interconnections to the
elements and preferably take a picture as a record. It may be possible to leave some of
the interconnection links in place while changing an element.
On each side disconnect the tail of the element from its brass electrical terminal block.
Remove the interconnections to each element if necessary.
Remove the screw holding the connection block carrier bracket from the side of the
furnace chamber.

Remove the plug of insulation blanket around the element’s tail and the ceramic tube
acting as a carrier and a guide for the element.

20
It will now be possible to slide out the element. The second person assists by guiding
the element from above.
Feed in a new element on its tube carrier and again a second person can assist by
guiding it in from above until the element sits centrally.
Once central replace the plug of insulation blanket around the element’s tail and the
ceramic tube acting as a carrier and a guide for the element.
Pass the tail of the element through its fixing hole in the terminal block and refit the
connection block carrier bracket to the furnace chamber.
Tighten up the connection bolt to the tail of the element and trim off any surplus with
wire cutters.
Replace any links removed to each element and replace the top of the furnace
chamber, the top panel and side panels. Replace any links that show signs of
deterioration.
Run the furnace up to the normal operating temperature for one cycle. When cool
switch off and electrically isolate and remove the side panels. Check the tightness of all
electrical connections.
6.6.2 Bottom Element Replacement 1200 °C Models
The furnace typically has 15 wire wound elements that just sit in grooves in the brick
work that is part of the hearth base. The elements are not supported on ceramic tubes.
It is not necessary to remove the hearth tile to fit these elements.
The replacement method is generally similar to that for the top elements above.
Remove the side panels. Disconnect the element tails, the interconnection links if
needed and remove the connection block retaining bracket.
Remove the plug of insulation blanket around the element’s tail and the ceramic tube
acting as a carrier and a guide for the element.
It will now be possible to slide out the element. If necessary remove any debris from
the slot the element sits in with a tube fitted to a vacuum cleaner.
The technique to fit the new element is for the second person to pass through a tube
typically 10 to 15 mm outside diameter from one side. The tail of the element is
positioned in the internal bore of the tube. The element is then gently inserted by the
first person from the other side and the tube is withdrawn and acts as a guide so that
the element does not snag while passing through the slot.
Once central replace the plug of insulation blanket around the element’s tail and the
ceramic tube acting as a carrier and a guide for the element.
Pass the tail of the element through its fixing hole in the brass terminal block and refit
the connection block carrier bracket to the furnace chamber.
Tighten up the connection bolt to the tail of the element and trim off any surplus with
wire cutters.
Replace any links removed to each element and replace side panels. Replace any links
that show signs of deterioration.
Run the furnace up to the normal operating temperature for one cycle. When cool
switch off and electrically isolate and remove the side panels. Check the tightness of all
electrical connections.

21
 6.7 Fuse Replacement
Fuses are marked on the wiring diagram with type codes, e.g. F1, F2. For more
information on fuses refer to section 9.0.
Depending on model and voltage, the different fuse types may or may not be fitted.
If any fuse has failed, it is advisable for an electrician to check the internal circuits.
Replace any failed fuses with the correct type. For safety reasons do not fit larger
capacity fuses without first consulting Carbolite Gero.
The fuses are located at the cable entry point. Remove the back panel or control box
back panel to gain access to the fuses.

22
7.0 Fault Analysis

A. Furnace Does Not Heat Up

The HEAT The heating element Check also that the SSR is
1.
light is ON has failed working correctly
The HEAT The controller shows a
The thermocouple has broken or
2. light is very high temperature
has a wiring fault
OFF or code such as S.br
The controller shows a The door switch(es) (if fitted) may
low temperature be faulty or need adjustment
The contactor/relay (if fitted) may
be faulty
The heater switch (if fitted) may
be faulty or need adjustment
The SSR could be failing to switch
on due to internal failure, faulty
logic wiring from the controller, or
faulty controller
There are no lights Check the supply fuses and any
glowing on the fuses in the furnace control
controller compartment
The controller may be faulty or
not receiving a supply due to a
faulty switch or a wiring fault.

23
 B. Product Overheats
Product only heats
The controller
up when the
1. shows a very high The controller is faulty
instrument switch is
temperature
ON
The thermocouple may be
The controller
faulty or may have been
shows a low
removed out of the heating
temperature
chamber
The thermocouple may be
connected the wrong way
around
The controller may be faulty
Product heats up Check for an accidental
The SSR has failed
2. when the instrument wiring fault that could have
"ON"
switch is OFF overloaded the SSR

24
8.0 Wiring Diagrams
In all models the safety switch in the diagram is a positive-break door switch.
EMC Filters (if fitted): dependent on the model there may be one filter, or more than
one fitted in parallel. The circuit diagram examples do not show multiple filter
arrangements.
ISOLATOR: the industrial models have an internal isolator which is not shown in these
diagrams.

8.1 WA-33-30
Connections below show 3-phase +N with indirect safety switches.

Key

F1, F2, F3 Fuses

FIL Filter (if fitted)

C Controller

TC Control Thermocouple Cables

R Relay BU Blue
R1/1, R1/2, R1/3 Relay contactor R Red
SW Instrument Switch(es) BL Black
SSW Safety Switch GR/Y Green + Yellow
EL Element G Grey
SSR Solid State Relay P Pink
N Neutral

L Live

PE Earth

25
 8.2 WA-33-31
Connections below show 3-phase +N with indirect safety switches and over-
temperature control.

Key

F1, F2, F3 Fuses

FIL Filter (if fitted)

C Controller

TC Control Thermocouple

OT Over-Temperature Controller Cables

OTC Over-Temperature Thermocouple BU Blue
R Relay R Red
R1/1, R1/2, R1/3 Relay contactor BL Black
SW Instrument Switch(es) GR/Y Green + Yellow
SSW Safety Switch G Grey
EL Element P Pink
SSR Solid State Relay

N Neutral

L Live

PE Earth

26
8.3 WA-U3-30
Connections below show 3-phase +N with indirect safety switches.

27
 Key

F1, F2, F3 Fuses

FIL Filter (if fitted)

C Controller

TC Control Thermocouple Cables

R1, R2, R3 Relay BU Blue

R1/1, R1/2, R2/1, R2/2, R3/1, R3/2 Relay contactor R Red

SW Instrument Switch(es) BL Black

SSW Safety Switch GR/Y Green + Yellow

EL Element G Grey

SSR Solid State Relay P Pink

N Neutral

L Live

PE Earth

Products with this wiring arrangement may be converted between the following supply
voltages (please refer to the table within section 9.0 for compatible phases with the
product):
l 3-phase + neutral in the range 380/220 V - 415/240 V
l 3-phase delta in the range 220 V - 240 V
l Single phase in the range 220 V - 240 V
l 208 V model: can be converted between 208 V delta and 208 V 1-phase
Please contact Carbolite Gero Service for details.

28
8.4 WA-U3-31
Connections below show 3-phase +N with safety switches and over-temperature
control.

29
 Key

F1, F2, F3 Fuses

FIL Filter (if fitted)

C Controller

TC Control Thermocouple
Cables
OT Over-Temperature Controller
BU Blue
OTC Over-Temperature Thermocouple
R Red
R1, R2, R3 Relay
BL Black
R1/1, R1/2, R2/1, R2/2, R3/1, R3/2 Relay contactor
GR/Y Green + Yellow
SW Instrument Switch(es)
G Grey
SSW Safety Switch
P Pink
EL Element

SSR Solid State Relay

N Neutral

L1, L2, L3 Live

PE Earth

Products with this wiring arrangement may be converted between the following supply
voltages (please refer to the table within section 9.0 for compatible phases with the
product):
l 3-phase + neutral in the range 380/220 V - 415/240 V
l 3-phase delta in the range 220 V - 240 V
l Single phase in the range 220 V - 240 V
l 208 V model: can be converted between 208 V delta and 208 V 1-phase
Please contact Carbolite Gero Service for details.

30
9.0 Fuses and Power Settings

9.1 Fuses
F1-F3: Refer to the circuit diagrams.

Internal Fitted if supply cable fitted.

38 mm x 10 mm type F fitted on
F1 Supply Fitted on board to some types EMC filter circuit board(s)
Fuses of EMC filter.

Fitted on board to some types 2 Amps glass type F

Auxiliary of EMC filter.
F2 On board: 20 mm x 5 mm
Circuit Fuses May be omitted up to 25 Amp/
phase supply rating. Other: 32 mm x 6 mm

Heat Light May be omitted up to 25 Amp/ 2 Amps glass type F

F3
Fuses phase supply rating. 32 mm x 6 mm

Required if no supply cable

Customer See rating label for current;
fitted.
Fuses See table below for fuse rating.
Recommended if cable fitted.
For rating values please contact Carbolite Gero Service. Please have the serial number
available from the data plate located next to the power inlet.

9.2 Power Settings

The power limit settings (parameter OP.Hi) for this model are voltage dependant. The
figures represent the maximum percentage of time that controlled power is supplied to
the elements. Do not attempt to “improve performance” by setting a value higher than
the recommended values. To adjust the parameter refer to the "Changing the
Maximum Output Power" of the control section of the manual.
For rating values please contact Carbolite Gero Service. Please have the serial number
available from the data plate located next to the power inlet.

31
 10.0 Specifications
Carbolite Gero reserves the right to change the specification without notice.
Max Max Chamber Size Approx
Model Temp Power Capacity
(°C) (kW) H W D (l)
Chamber furnaces heated by resistance wire resting on refractory formers.
LCF 12/560 1200 45 500 750 1500 560

10.1 Environment
The models listed in this manual contain electrical parts and should be stored and used
in indoor conditions as follows:

Temperature: 5 °C - 40 °C

Relative Maximum 80 % up to 31 °C decreasing linearly to 50 % at 40

humidity: °C

32
 Notes

Service Record
Engineer Name Date Record of Work
The products covered in this manual are only a small part of the wide range of ovens,
chamber furnaces and tube furnaces manufactured by Carbolite Gero for laboratory
and industrial use. For further details of our standard or custom built products please
contact us at the address below, or ask your nearest stockist.

For preventive maintenance, repair and calibration of all furnace and oven products,
please contact:
Carbolite Gero Service
Telephone: + 44 (0) 1433 624242
Fax: +44 (0) 1433 624243
Email: ServiceUK@carbolite-gero.com
Carbolite Gero Ltd,
Parsons Lane, Hope, Hope Valley,
S33 6RB, England.
Telephone: + 44 (0) 1433 620011
Fax: + 44 (0) 1433 621198
Email: Info@carbolite-gero.com
www.carbolite-gero.com
Copyright © 2021 Carbolite Gero Limited