ESABMig C420

ESABMig C420s

Service manual

0349 300 041 030410 Valid for serial no. 237–xxx–xxxx

Downloaded from www.Manualslib.com manuals search engine

 READ THIS FIRST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
TECHNICAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Component description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
ESABMig C420/C420w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
ESABMig C420/C420w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
ESABMig C420s/C420sw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
ESABMig C420s/C420sw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
DESCRIPTION OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AP1 Control board (for C420w/C420) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AP1:1 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AP1:2 Activation, contactor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AP1:3 Activation, gas valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
AP1:4 2–stroke / 4–stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
AP1:5 Burn–back time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
AP1:6 Wire feed speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
AP1:7 Motor driving / braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
AP1:8 Tachometer input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
AP1:9 Creep start, Current relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
AP1:10 Start / Stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AP1:11 Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AP1 Component positions (0486 205 886) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
AP1 Component positions (0486 205 882) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
AP2 Digital instrument (option for C420w/C420) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
AP2:1 Calibration and voltage correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
AP2:2 Connections to the digital instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
AP1 (0349 303 176), AP2 (0349 303 193) control boards
(for C420s/C420sw) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
AP1:1 Power suply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
AP1:2 Start / stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
AP1:3 Welding current detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
AP1:4 Welding parameter setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
AP1:5 Motor driving / braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
AP1:6 Burnback time, contactor, gas valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
AP1:7 2–stroke / motor test (inching) / 4–stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
AP1:8, AP2:1 Measuring and displaying of welding parameters . . . . . . . . . . . . . . . . . . . . . . . . . 26
AP1:9 Synergy control presets and indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
AP3 Control board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
AP3:1 Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
AP3:2 Overheating protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
AP3:3 Water connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
AP3:4 Water flow guard (ESABMig C420w – optionally) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
AP3:5 Idle mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
AP3 Component positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
What is ESD? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Placing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Assembly of components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Electrical installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Mains power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

TOCe –2–

Downloaded from www.Manualslib.com manuals search engine

 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
CONNECTIONS AND CONTROL DEVICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
ESABMig C420w/C420 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
ESABMig C420sw/C420s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Setting the wire feed pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
FUNCTIONS EXPLANATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ESABMig C420w/C420 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
ESABMig C420sw/C420s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Inspection and cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Topping up the coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
ORDERING OF SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

TOCe –3–

Downloaded from www.Manualslib.com manuals search engine

 READ THIS FIRST
Maintenance and repair work should be performed by an experienced person, and
electrical work only by a trained electrician. Use only recommended replacement parts.
This service manual is intended for use by technicians with electrical/electronic training for
help in connection with fault–tracing and repair.
Use the wiring diagram as a form of index for the description of operation. The circuit
board is divided into numbered blocks, which are described individually in more detail in
the description of operation. All component names in the wiring diagram are listed in the
component description.
This manual contains details of all design changes that have been made up to and
including March 2003.

The ESABMig C420w/C420 and ESABMig C420sw/C420s are designed and tested in
accordance with international and European standard IEC/EN 60974–1 and EN 50199.
On completion of service or repair work, it is the responsibility of the person(s) etc.
performing the work to ensure that the product does not depart from the requirements
of the above standard.

WARNING
Many parts of the power unit are at mains voltage.

INTRODUCTION
The ESABMig C420w/C420sw are step–controlled compact welding power units incorporating wire
feed mechanism intended for MIG/MAG welding with solid wires of steel, stainless steel or aluminium,
and cored wires with or without shielding gas. The ESABMig C420w/420sw are equipped with cooling
liquid system for welding torch. The ESABMig C420/420s are not equipped with cooling system and
can operate only with appropriate gas cooled torches.
The ESABMig C420w/420 is equipped with standard control unit (manual setting of all welding
parameters) and ESABMig C420sw/420s contains additional synergy control facility (preprogrammed
welding parameters).
The power units are fan–cooled and equipped with thermal overload protection.
The machines can be fitted with a flow guard (C420sw/C420w).

TECHNICAL DATA
ESABMig C420/C420w ESABMig C420s/C420sw
Voltage 400–415V, 3~50/60Hz 400–415V, 3~50/60Hz
Permissible load
at100 % duty cycle 315 A/30V 315 A/30V
at 60 % duty cycle 400 A/34V 400 A/34V
at 50 % duty cycle 420 A/35V 420 A/35V
Setting range (DC) 50A/16,5V–420A/35V 50A/16,5V–420A/35V
Open circuit voltage 14–47V 14–47V

doce1 –4– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Open circuit power 520W 520W
with cooling unit 730W 730W
Efficiency at max current 77% 77%
Power factor at max current 0,92 0,92
Control voltage 42V, 50/60Hz 42V, 50/60Hz
Wire feed speed 1,9 – 25,0m/min 1,6 – 25,0m/min
Burnback time 0 – 0,5s 0 – 0,35s
Creep start OFF / ON ON
2/4 stroke 2/4 2/4/
Welding gun connection EURO EURO
Max diameter of wire bobbin 300mm 300mm
Wire dimension range 0,6 – 1,6mm 0,6 – 1,6mm
Dimensions lxwxh 935 x 640 x 800mm 935 x 640 x 800mm
Weight 209kg 209kg
with cooling unit 217kg 217kg
Operating temperature –10 to +40oC –10 to +40oC
Enclosure class IP 23 IP 23
Application classification

ESABMig C420/C420w
Voltage 230/400–415/500V 3~50Hz 230/440–460 3~60Hz
Permissible load
at100 % duty cycle 315 A/30V
at 60 % duty cycle 400 A/34V
at 50 % duty cycle 420 A/35V
Setting range (DC) 50A/16,5V–420A/35V
Open circuit voltage 14–47V
Open circuit power 520W
with cooling unit 730W
Efficiency at max current 77%
Power factor at max current 0,92
Control voltage 42V, 50/60Hz
Wire feed speed 1,9 – 25,0m/min
Burnback time 0 – 0,5s
Creep start OFF / ON
2/4 stroke 2/4
Welding gun connection EURO
Max diameter of wire bobbin 300mm
Wire dimension range 0,6 – 1,6mm
Dimensions lxwxh 935 x 640 x 800mm
Weight 209kg
with cooling unit 217kg
Operating temperature –10 to +40oC
Enclosure class IP 23
Application classification

doce1 –5– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 WIRING DIAGRAM

Component description

WARNING !
STATIC ELECTRICITY can damage circuit
boards and electronic components.
S Observe precautions for handling electrostatic
sensitive devices.
ESD S Use proper static–proof bags and boxes.

AP1 Control circuit board with control electronics ( see – page XX and YY ).

AP2 Digital instrument ( see page XX and YY ).

AP3 Control circuit board ( see – page XX).

C1 – C3 EMC – capacitors 2 uF 450 V.

C4 Capacitor, 3 uF 400 V. Start and run capacitor for fan motor EV1.

C5 Capacitor, 6 uF 400 V. For speed reduction of the cooling fan.

C6 – C8, CES Suppression capacitors 0.1 uF 250 V.

EV1 Fan.

G1 Tachogenerator, 660 Hz output at a wire speed of 25m/min.

The tachogenerator is incorporated in motor M2
( ESABMig C420w/C420 only).

H1 Indicating lamp, green. Lights when switch QF1 is in the ON position.

H2 Indicating lamp, yellow. Lights when thermal overload ( thermal cut–out active).
If the machine is equipped with flow guard, the lamp also indicates loss of
coolant.

KM1 Contactor 42 V 50 Hz. For energising of the welding circuit.

M1 Pump motor, 230 V 50 Hz 0.2 kW. Only machines with water cooler.

M2 Motor, rated voltage 42 V DC (wire feed unit).

QF1 Main ON/OFF switch.

QF2 Welding voltage selector (coarse setting).

QF3 Welding voltage selector (fine setting).

RS Shunt, 60 mV / 400 A (optional accessory).

doce1 –6– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 S2 ELP switch – on the cooling water outlet, activates pump M1.
Only in machines with water cooler.

SL1 Flow guard (optional accessory; only in machines with water cooler.).

ST1 Thermal switch – overheating protection, in the inductor L1 ( NC, 120oC).

ST2 Thermal switch – overheating protection, on the bridge V1 ( NC, 120oC).

ST3 Thermal switch – change–over the speed of the fan motor EV1 (NO, 80oC).
The switch opens when the machine temperature falls to 60oC.

TC1 Control power supply transformer.

TC2 Transformer for CO2 heater (optional accessory).

TM1 Main transformer.

V1 Diode bridge (3ph.).

V2 Diode bridge (1ph.; ESABMig C420sw/C420s only).

XB1 EURO–Connector, for welding gun connection.

XB2 – XB4 Welding current socket, single––pole (return current wire).

XT1 9 pole/ 3 pole – terminal block

(machine with/without water cooler–respectively).

XT2 Auxilary 1 pole connector.

XT3 2 pole terminal block (optional accessory).

XTP Terminal block for polarity reversing .

doce1 –7– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 ESABMig C420/C420w

doce1 –8– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 ESABMig C420/C420w

doce1 –9– Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 ESABMig C420s/C420sw

doce1 – 10 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 ESABMig C420s/C420sw

doce1 – 11 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 DESCRIPTION OF OPERATION
This description of operation describes the function of circuit boards and other components
in the power unit. It is divided into sections, numbered to correspond to the circuit board
numbers and divisions into function blocks.

AP1 Control board (for C420w/C420)

Note: AP1 – 0486 205 882 only for machines manufactured till May 2003
Note: AP1 – 0486 205 886 only for machines manufactured after May 2003

AP1:1 Power supply

The wire feed unit receives 42 V from the control power supply transformer in
the welding power unit via relay contact on AP3.
42 V AC is supplied to the welding gun trigger switch, the gas valve and the
contactor.
DC power supplies
Diodes D30 – D33 rectify the 42 V supply to 60 V. Capacitor C61 smooths the
supply, which is then used to power the wire feeder motor.
Transistor Q2 is a pre–regulator that drops the voltage from 60 V to 20 V. Q2 is
current–limited to about 200 mA.
VR1 and VR2 are voltage regulators, producing 5 V and 15 V respectively. The
circuit board’s microprocessor monitors the voltages. If the 15 V supply falls
below 13 V, the wire feed unit is stopped.

AP1:2 Activation, contactor

The start signal is connected to contactor KM1.

doce1 – 12 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:3 Activation, gas valve

The gas valve is connected to connectors F04 and F05.

AP1:4 2–stroke / 4–stroke

2–stroke
When switch SP2 is open, 2–stroke control mode is selected. This means that
closing the welding gun trigger switch starts the wire feed motor, opens the gas
valve and closes the power unit contactor.
Releasing the switch stops the motor, releases the contactor and closes the
gas valve. If burn–back time is operative, welding ceases after the burn–back
time has elapsed.

4–stroke
When switch SP21 is closed, 4–stroke control mode is selected. This means
that first closure of the trigger switch operates the gas valve, with the wire feed
motor starting, and the power unit contactor operating, when the trigger switch
is released.
Closing the trigger switch for the second time stops the motor and
de–energises the contactor in the power unit. Releasing the switch closes the
gas valve. If burn–back time is operative, welding ceases after the burn–back
time has elapsed.

doce1 – 13 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:5 Burn–back time

The burn–back time is the time from when motor braking starts until the
machine contactor opens. It can be adjusted by potentiometer RP2 between 0
and 0.5 seconds.

AP1:6 Wire feed speed

Potentiometer RP1 controls the wire feed speed over a range from 1.9 to 25
metres/minute.

doce1 – 14 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:7 Motor driving / braking

Driving
The motor is powered by the smoothed +60 V supply. Pulse width modulation,
controlled by transistor Q3, is used to vary the motor voltage. The pulse
frequency is 12 kHz, and the maximum conducting time of the pulses is 97% of
the pulse cycle time. Freewheeling diode D11 maintains motor current during
the pulse breaks.
At a drive roller speed of 266 r/min, the wire feed speed is 25 m/min.
The voltage drop across resistor R92 provides a signal that is proportional to
the motor current. When the current exceeds 15.4 A, IC6:2 turns off the gate
pulse to Q3. When the current drops, Q3 conducts again at the next gate
pulse.
Braking
When the motor starts, capacitor C60 charges up to 15 V, with zener diode
D20 limiting the voltage across it. Braking is activated by the optocoupler IC3.
When the transistor in IC3 is turned on by the LED, 15 V from capacitor C60 is
connected to the gate of transistor Q4. Transistor Q4 turns on and short
circuits the motor through the resistors R85–R87 (AP1 – 0486 205 886). The
resistors limit the braking current to about 20 A.
NB: On AP1 – 0486 205 882 only R86 & R86 are installed.

doce1 – 15 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:8 Tachometer input

The tachometer G1 is fitted inside the motor casing. Comparator IC5;2

converts the sine wave signal from the tachogenerator to a square wave at the
same frequency.

AP1:9 Creep start, Current relay

Creep start
The creep start function is activated when switch SP1 is:
S open (AP1 – 0486 205 886)
S closed (AP1 – 0486 205 882)
Creep start means that the motor runs at a speed of 1.9 m/minute until the
current relay is activated. When the relay operates, the speed increases to the
set speed. If the current relay has not operated within one second after
starting, the motor increases to the set speed.
Current relay
The current relay operates if the welding current exceeds 20 A.

doce1 – 16 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:10 Start / Stop

The trigger switch in the welding gun is supplied at 42 V AC. Closing the switch
energises optocoupler IC10, pulling down the voltage across C46.

AP1:11 Processor
The processor stores the machine program. It monitors the power supply
voltages: if the voltages drop to too low a level, wire feed is stopped, as
described in section AP1:1 above.
The processor also monitors speed. If the wire speed deviates from the set
value by more than 1.5 m/min for more than five seconds, wire feed will be
stopped.

doce1 – 17 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1 Component positions (0486 205 886)

doce1 – 18 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1 Component positions (0486 205 882)

doce1 – 19 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP2 Digital instrument (option for C420w/C420)

AP2:1 Calibration and voltage correction

The meter has a possibility of the voltage and current calibration, as well as a
possibility of the current–dependant voltage correction, to show a voltage
approximately equal to the actual arc voltage.
Since all meters are factory calibrated it is recommended to carry out a second
calibration only if it’s needed. In most applications a zero voltage correction
(no correction) is factory adjusted.
For the calibration an accurate reference meter and a resistance load are
required. The resistance load should force at least 100A current flow.
For calibration following actions should be done:
1 Switch the machine on and load it. The meter should indicate voltage and
current presence.
2 Press simultaneously both pushbuttons placed on the meter PC board. In
sequence, symbols of the calibration modes appear: ”U” – voltage calibration,
”I” – current calibration, ”dU” – voltage correction. Release the buttons as the
required mode appears.
3 Adjust the voltage or the current value equal to the value shown by the
reference meter by means of the pushbuttons: S1 – ”+”, S2 – ”–”.
Voltage calibration mode
The reference meter should be connected to the same potentials as a
calibrated meter. Exclusively in this mode a voltage without correction is shown
on display.
Voltage reduction mode
The reference meter should be connected to the end of mass cable and to the
torch current tip, which are connected to the external load. In this mode, as
well as during the regular work, the meter shows a voltage taking in account
voltage drops on cables and welding torch. An adjustment of the voltage
correction should be carried out only in assumption of the proper voltage
calibration and in the presence of load current above 100A.

doce1 – 20 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP2:2 Connections to the digital instrument

doce1 – 21 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1 (0349 303 176), AP2 (0349 303 193) control boards
(for C420s/C420sw)

AP1:1 Power suply

The circuit board uses one supply voltage: 42VAC ( rectified by the bridge V2)
for power supply to the motor and control circuitry.

+60VS power supply from diode V1 through R1A, R1 – is regulated to 15V by

voltage regulator A1
+60VS from V1 through R3, V3A, R4 is regulated to +5V by voltage regulator
A2,
+15V is used for supplying of the motor control electronic
+5V – supplies microprocessor control circuits
+60V/+60VS power supply
+60V – is used for motor control
+60VS – is used for energizing of some input control circuits (see next
sections)
These voltages may vary (with load/mains voltage deviation) – from –15% to
+10%.
+26V (intermediate voltage for A2) – also supplies the relays K1 and K2 (on
the pcb)

AP1:2 Start / stop

Closing contact on the welding torch starts the welding process – or only
motor M2 (motor test/inching/) – depending on control mode selection (see –
section 7)
NOTE: When the machine is turned–on while the torch trigger is depressed –
operation of the machine is disabled ( LED ”17” on the front control panel
emits red light).

doce1 – 22 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:3 Welding current detection

Signal from current relay is used for detection of welding current presence –
after closing of the torch trigger.

AP1:4 Welding parameter setting

NOTE: 1.In the AP1 diagrams in the next sections – there are shown electronic
reference potentials GNDCA and GND (not marked); they are both
galvanically connected and accessible at test point TP1.
NOTE: Device numbers ”xx” refer to the chapter: ”OPERATION / Connections
and control devices”.
A. Wire feed speed / creep start
The wire speed setting range is 1,6 to 25 meter/minute. Speed value is set by
the potentiometer RP4 (”12”) in the front control panel ( in ”standard control
mode”, see sec. 9A) or by the programm stored in the microprocessor
(”synergy control mode”).
The upper limit of the speed reference signal may be adjusted by trim–pot.
R51A : 4.9V at TP5 (refered to TP1 – when RP4 max – in ”standard mode”)
corresponds to 25m/min.
Additional speed reference adjustment is performed by the trim potentiometer
R53, it allows to shift upwards the whole speed range within 0 – 0,5m/min – so
as to correct especially the minimum speed of wire (Note: this correction is not
shown on speed reference display ”14”).
Calibration of the actual motor speed (i.e. matching the speed reference
signal) is carried out by the trim potentiometer R7 on the pcb (it may be
necessary only when wire feed motor is changed).

doce1 – 23 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 There is built–in ”creep speed” function in the program (ca 60% of work speed,
but not less than 1,2m/min), i.e. welding starts with reduced wire speed and
when welding current relay picks–up (see, sec.3), the speed rise up to the
value pre–set with RP4. Independently of the current relay, after ca 0,77 sec.
the speed increases automatically to the work speed.
V–REF voltage is the analog reference signal for motor speed control circuit,
the digital reference speed is displayed on the front control panel (display ”14”,
lower row with selected ”m/min”).
In ”standard control mode” (Synergy = OFF with switch ”21” in wire feeder
compartment) welder may set the wire speed in full range with the
potentiometer RP4. When ”synergy control mode” is active (switch ”21” in any
position but OFF) signal from RP4 serves only as correcting value within
+/–20% of preset in microprocessor program speed value.
Note: That correction is counted from the middle point of RP4.
B. Spot welding setting

Turning right the potentiometer with switch RP3 in the front panel (”13”) welder
may select the function ”spot welding”, i.e. time controled welding process.
RP3 allows to adjust the process duration within 0.5 – 4.5 sec.
Normal welding is selected – when RP3 is set in the utmost left position.

AP1:5 Motor driving / braking

Driving
The motor is powered by the smoothed +60 V supply. Pulse width modulation
on transistor V8 controls the motor voltage. The pulse frequency is about 16
kHz, and maximum conduction time of the pulses is about 95% of the pulse
cycle time. During the off parts of the pulse cycle, the motor current freewheels
through diode V10.

doce1 – 24 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 At 42V motor supply voltage, the wire feed roller speed is 258 r/min +/–5%. At
a roller speed of 265r/min, the wire feed speed is 25 m/min.
Speed control
The gate pulses for transistor V8 are generated by a PWM circuit, which
compares speed reference from microprocessor electronic with signal
proportional to the motor voltage (R10, R24).
Current limit
The current limit is set at 13 A. The motor current is measured by resistor R32
which produces a voltage drop proportional to the current (1A = 33mV).
The current limit restricts the conduction time of the gate pulses to transistor
V8.
Compensation of motor I x R voltage
Current signal allows to compensate voltage drop on motor armature
resistance so as to improve wire transportation at low speed settings
(Compensation is adjusted via trim potentiometer R9B, recommended setting
is 60 – 80 % of the pot.range).
Braking
Motor braking is activated by the turning on the V9 transistor; braking curent
flows thru R29A,R29B,R30, and its maximum value is limited to ca 18A.

AP1:6 Burnback time, contactor, gas valve

Burnback time
The burnback time is the time from when motor braking starts until the main
contactor opens. The burnback time can be adjusted from 0 to 0,35 seconds
with potentiometer R47on the pcb (signal to the microprocessor). R47 is
located in the auxilary control panel inside wire feed compartment (pos. ”23”).
Activation, contactor and gas valve
Contactor KM1 is switched on by the relay K1, which is controlled by transistor
V14.
Gas valve YV1 is controlled by V12 and K2. Valve YV1 opens in advance to
the contactor (gas preflow time – 0.27sec) and closes with delay (gas postflow
time – 0.4sec)

doce1 – 25 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:7 2–stroke / motor test (inching) / 4–stroke

With switch S1 on AP1 in the motor compartment (item ”24”), welder may
select the following control modes:
2–stroke
When the switch on welding gun is pressed, welding process starts (wire feed
motor, gas valve and power unit contactor are active). When switch on welding
is released, welding process stops (motor is immediately inactive, contactor is
inactive when burnback time is elapsed and gas valve is inactive with delay of
the postflow time ).
Motor test (inching)
When the switch on welding gun is pressed, only wire feed motor starts, gas
valve and contactor remain inactive.
4–stroke
When the switch on welding gun is pressed 1st time, only gas valve is turned
on, after releasing the switch welding process starts (motor and contactor are
active). Pressing the switch again stops the motor and deactivates the
contactor (after burnback time); opening the switch cuts–off the gas flow.

AP1:8, AP2:1 Measuring and displaying of welding parameters

NOTE: All circuits of the U/I measurment part of the AP1 are galvanically
isolated from other circuits on AP1, hence the reference potentials: GNDB (test
point TP7) connected with welding power circuit, and GND/GNDCA (test point
TP1) MUST be kept separated!
U/I measurement inputs

doce1 – 26 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Negative voltage (maximum 60V!) and positive 60mV shunt signal are applied
to the AP1. Those signals are converted into pulse–frequency signals (FU* and
FI* respectively) that are processed in microprocessor.
S FU* – frequency is 6,4 kHz for – 40V input (adj. by R97)
S FI* – frequency is 6,4 kHz for +60mV / 400A / input (adj. by R88)
NOTE: signals on TP7 and TP8 are referred to TP6!
Parameters displaying and display mode selection

ESABMig C420s/C420sw is equipped with 2–row display, located on AP2,

which includes 2 selectors for choosing of displayed parameters (items
”14”,”15”,”16”)
With SV1 (switch ”15”) [V] or [A] display is selected (open contact
correspondents to [A]).
With SV2 (switch ”16”) recommended thickness of welded material [mm] or
reference wire speed [m/min] is selected for displaying (open contact
corresponds to [m/min]).
Display ”14” on AP2 operates in 3 modes:
S Before start of welding (bright indicators), expected values of V or A (only in
”synergy mode”), and recommended material thickness or wire speed
reference are displayed.
S During welding (bright indicators), actual values of V or A are displayed.
S After stop of welding (dimmed indicators), memorised values of V and A are
displayed (”HOLD”– function)

doce1 – 27 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP1:9 Synergy control presets and indications

Synergy ON/OFF and material / gas selection

10–position selector S2 on AP1 (item ”21” in wire feeder compartment) serves
for selection of control mode:
1st position,”STANDARD control mode”, i.e. SYNERGY is OFF”
remaining positions correspond to ”SYNERGY control mode”, for presetting of
different sets of electrode material and shield gases
NOTE: S2 output is BCD–coded

Wire diameter presetting

Presetting of wire electrode diameter is performed with the potentiometer R61

on AP1 (item ”22” in feeder compartment).
Welding voltage selection
Welder may select required value of welding voltage with switch QF2 (coarse
setting) and QF3 (fine setting). Each position of the voltage selectors is
identified by microprocessor so as to determine optimum welding parameter.
In ”standard control mode”, there are no restrictions for voltage selection, i.e. it
is possible to weld with any selected parameters (see NOTE1 below).
In ”synergy control mode”, depending on the preset wire diameter and
material/gas, operation is enabled only for optimum values of voltage (LED
”17” in the front panel lights green and all indications are active, otherwise ”17”
is red, other indications are inactive and operation is disabled).
NOTE1: Independently on the selected control mode, operation of the machine
is disabled (LED ”17” in red) in following cases:
S any of the selectors QF2, QF3 is operated during welding process
S mains voltage deviation from 400V is more then +/– 15%

doce1 – 28 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 NOTE2: In above diagram are shown contacts of the selectors QF2 and QF3
for 400V machine version,for another machine versions, contact designation
may differ from those above! (refer to the relevant wiring diagrams in order to
identify actual connection).
Indication of synergy control status

Depending on parameter presets made by welder (voltage, material/gas, wire

diameter), microprocessor determines and displays necessary data and
signals.
When the combination of the presets is incorrect or prohibited, red LED H4
(”17”) warns the operator and all control function are disabled. (See also –
NOTE in section 2 and NOTE1 in section 9C)
When all presets are optimal (correct), green LED H4 (”17”) informs that
welding is enabled.
When welding functions are enabled, there are displayed expected welding
parameters (see section 8B) and also relevant green LED H5, H6 or H7 (”18”)
indicates recommended inductance output for the return cable (Lmin, Lmed;
Lmax).

doce1 – 29 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP3 Control board
Control board AP3 switches on and off. the fan, pump and supply voltage for
AP1.
Signal levels:
S inputs: 60V dc
S ouputs: relays 16A/250V + indicating LED diodes.

AP3:1 Start
When switched on, indicating lamps are tested for 2 seconds. Normally, if the
machine is not overheated, it should start to work in idle mode, which is
indicated by blinking of the supply–ON lamp. The fan and the coolant pump
are stopped.The fan starts from the first start of welding. The coolant pump
starts at the same moment, if it is switched on by means of the ELP switch
located on the water outlet to the welding gun.

AP3:2 Overheating protection

The power source includes 2–step control of the fan speed and overheating
protection. If temperature crosses the threshold point, the fan starts to operate
with increased speed. If the internal temperature becomes too high, the supply
of the PCB – AP1 is cut–off – disabling operation of the machine. This state is
indicated by permanent lighting of the orange indicating lamp on the front of
the unit. AP1 supply restores automatically when the temperature falls down.
The thermal overload cutout ST1 is fitted in the inductor winding L1, it opens at
temperature of 120 oC. ST2 is located on the heatsink of the V1 rectifier and
opens at 120 oC. NC–contacts of the ST1 and ST2 are connected in series –
activating thermal overload alarm. Thermal switch ST3 is also located in the L1
winding, its NO–contact at 80 oC turns–over the fan speed.

doce1 – 30 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 AP3:3 Water connection
The ESABMig C420w has a sensor ELP, ESAB Logic Pump, which senses
whether the water hoses of the welding gun are connected. When a
water–cooled welding gun is connected, the water pump is activated by means
of control board AP3.

AP3:4 Water flow guard (ESABMig C420w – optionally)

The water flow guard interrupts and disables the welding in the event of loss of
coolant. This state is indicated by blinking of the orange indicating lamp on the
front of the power source. If there is a lack a coolant flow, after 1 min the pump
is switched off and latched in this state. The pump restarts from this state
along with starting of welding.

AP3:5 Idle mode

When long inactivity of the machine – the control board AP3 turns the machine
to the idle mode. The fun is switched off 5 min after the last welding or after 5
min of work with decreased speed without welding. The pump is switched off 3
min after the last welding. When both fan and pump are switched off the
power–supply lamp on the front panel is blinking.

AP3 Component positions

doce1 – 31 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 SERVICE INSTRUCTIONS

WARNING !
STATIC ELECTRICITY can damage circuit
boards and electronic components.
S Observe precautions for handling electrostatic
sensitive devices.
ESD S Use proper static–proof bags and boxes.

What is ESD?
A sudden transfer or discharge of static electricity from one object to another. ESD stands for
Electrostatic Discharge.

How does ESD damage occur?

ESD can cause damage to sensitive electrical components, but is not dangerous to people.
ESD damage occurs when an ungrounded person or object with a static charge comes into
contact with a component or assembly that is grounded. A rapid discharge can occur,
causing damage. This damage can take the form of immediate failure, but it is more likely
that system performance will be affected and the component will fail prematurely.

How do we prevent ESD damage?

ESD damage can be prevented by awareness. If static electricity is prevented from building
up on you or on anything at your work station, then there cannot be any static discharges.
Nonconductive materials (e.g. fabrics), or insulators (e.g. plastics) generate and hold static
charge, so you should not bring unnecessary nonconductive items into the work area.
It is obviously difficult to avoid all such items, so various means are used to drain off any
static discharge from persons to prevent the risk of ESD damage. This is done by simple
devices: wrist straps, connected to ground, and conductive shoes.
Work surfaces, carts and containers must be conductive and grounded, use only antistatic
packaging materials. Overall, handling of ESD–sensitive devices should be minimized to
prevent damage.

doce1 – 32 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 INSTRUCTIONS
This chapter is an extract from the instructions for ESABMig C420w/C420 and ESABMig
C420sw/C420s

SAFETY
Users of ESAB welding equipment have the ultimate responsibility for ensuring that anyone who
works on or near the equipment observes all the relevant safety precautions. Safety precautions
must meet the requirements that apply to this type of welding equipment. The following recommen-
dations should be observed in addition to the standard regulations that apply to the workplace.

All work must be carried out by trained personnel well–acquainted with the operation of the welding
equipment. Incorrect operation of the equipment may lead to hazardous situations which can result
in injury to the operator and damage to the equipment.
1. Anyone who uses the welding equipment must be familiar with:
S its operation
S location of emergency stops
S its function
S relevant safety precautions
S welding
2. The operator must ensure that:
S no unauthorised person is stationed within the working area of the equipment when it is
started up.
S no–one is unprotected when the arc is struck
3. The workplace must:
S be suitable for the purpose
S be free from draughts
4. Personal safety equipment
S Always wear recommended personal safety equipment, such as safety glasses, flame–proof
clothing, safety gloves.
S Do not wear loose–fitting items, such as scarves, bracelets, rings, etc., which could become
trapped or cause burns.
5. General precautions
S Make sure the return cable is connected securely.
S Work on high voltage equipment may only be carried out by a qualified electrician.
S Appropriate fire extinquishing equipment must be clearly marked and close at hand.
S Lubrication and maintenance must not be carried out on the equipment during operation.

WARNING!
Read and understand the instruction manual
before installing or operating.

doce2 – 33 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 INSTALLATION

WARNING!
This product is intended for industrial use. In a domestic environment this product may cause radio
interference. It is the user’s responsibility to take adequate precautions.

Lifting instructions
The power supply should be lifted by means of its lifting
eye. The handle is only intended for pulling it along the
ground.

Placing
Position the welding power source so that its cooling air inlets and outlets are not obstructed.

Assembly of components

WARNING!
During transport, the rear wheels of the power source are in their forward position.
Before use, place the wheels in their rear position.

doce2 – 34 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Electrical installation

Mains power supply

Check that the unit is connected to the correct mains power supply voltage, and that
it is protected by the correct fuse size. A protective earth connection must be made,
in accordance with regulations.

Rating plate with supply connection data

ESABMig C420w/C420sw 3∼ 50/60 Hz

Voltage V 400/415
Current A
at100% duty cycle 19
at 60% duty cycle 27
at 50% duty cycle 30
Cable area mm2 4x4
Fuse, slow A 25

NB: The mains cable areas and fuse sizes as shown above are in accordance with Swedish
regulations. They may not be applicable in other countries: make sure that the cable area and fuse
sizes comply with the relevant national regulations.

doce2 – 35 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 OPERATION
General safety regulations for the handling of the equipment can be found on
page 33. Read through before you start using the equipment!

WARNING!
Rotating parts can cause injury, take great care.

WARNING – TIPPING RISK!

There is a risk of tipping while transportation and operation, if the welding machine leans
more than 10o. In that case appropriate securing has to be provided !

CONNECTIONS AND CONTROL DEVICES

ESABMig C420w/C420

1 Mains supply switch 10 Connection for return cable (–), medium in-
ductance
2 Switch, coarse control 11 Connection for return cable (–), low induc-
tance
3 Switch, precise control 12 Knob for wire speed setting
4 Indicating lamp, power supply ON 13 Knob for selecting 2/4–stroke control mode
5 Orange indicating lamp, overheating and 14 Knob for selecting – creep start – ON/OFF
loss of coolant*
6 EURO – connector (for welding gun) 15 Knob for burn–back time setting
7 Connection for cooling water to the welding 16 Digital instrument – V / A
gun (Blue – with ELP** switch)
8 Connection for cooling water from the weld- 17 Water flow guard
ing gun (Red)
9 Connection for return cable (–), high induc-
tance
* Indicating loss of coolant, only when water flow guard is used
** ELP = ESAB Logic Pump

doce2 – 36 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 ESABMig C420sw/C420s

1 Mains supply switch 13 Knob for spot welding – ON/OFF and time
setting
2 Switch, coarse control 14 Digital display for welding parameters
3 Switch, precise control 15 Switch for display selection – Volt. or Amp
4 Indicating lamp, power supply ON 16 Switch for display selection – m/min or mm
5 Orange indicating lamp, overheating and 17 Lamp indicating status of synergy control
loss of coolant*
6 EURO – connector (for welding gun) 18 Lamps indicating recommended (–) current
output – max/med/min inductance
7 Connection for cooling water to the welding 19 Switch for ”Synergy”– ON/OFF and ma-
gun (Blue – with ELP** switch) terial/gas selection
8 Connection for cooling water from the weld- 20 Knob for selection of the wire diameter
ing gun (Red)
9 Connection for return cable (–), high induc- 21 Knob for burn–back time setting
tance
10 Connection for return cable (–), medium in- 22 Mode selector 2–stroke / motor test /
ductance 4–stroke
11 Connection for return cable (–), low induc- 23 Water flow guard
tance
12 Knob for wire speed setting / correction
* Indicating loss of coolant, only when water flow guard is used
** ELP = ESAB Logic Pump

doce2 – 37 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 doce2 – 38 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Setting the wire feed pressure
Start by making sure that the wire moves smoothly through the wire guide. Then set the
pressure of the wire feeder’s pressure rollers. It is important that the pressure is not too

ÏÏ ÏÏ
great.

ÏÏ
ÏÏ ÏÏ
ÏÏ
ÏÏ
ÏÏ ÏÏ
ÏÏ
ÏÏ
Fig 1 Fig 2

To check that the feed pressure is set correctly, you can feed out the wire against an
insulated object, e.g. a piece of wood.
When you hold the welding gun approx. 5 mm from the piece of wood (fig. 1) the feed
rollers should slip. If you hold the welding gun approx. 50 mm from the piece of wood, the
wire should be fed out and bend (fig. 2).

FUNCTIONS EXPLANATION
Start
When switched on, indicating lamps [4,5] are on for 2 seconds. Normally, if the
machine is not overheated, it should start to work in idle mode, which is indicated by
blinking of the supply ON lamp. The fan and the coolant pump are stopped. The fan
starts at the first start of welding. The coolant pump starts at the same moment, if it
is switched on with ELP switch on the water outlet [7].

Overheating protection
The power source has 2–step control of fan speed and overheating protection.
If temperature crosses the threshold point, the fan starts to run with increased
speed. If the internal temperature becomes too high, the welding is interrupted and
disabled. This state is indicated by permanent lighting of the orange indicating lamp
on the front of the unit. It resets automatically when the temperature falls down.

Water connection
The ESABMig C420w/C420sw have a sensor ELP, ESAB Logic Pump, which senses
whether the water hoses of the welding gun are connected. When a water cooled
welding gun is connected, the water pump is active.
It is recommended to switch the power source off by means of the mains switch
ON/OFF [1] for connecting the cooling water hoses to/from the ESABMig
C420sw/C420w.

doce2 – 39 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Water flow guard
The machines with cooling unit (C420w/C420sw) can be fitted with a water flow
guard (option – see page NO TAG).
The water flow guard interrupts and disables the welding in event of loss of coolant.
This state is indicated by blinking of the orange indicating lamp on the front of the
power source. If there is a lack a coolant flow, after 1 min the pump is switched off
and latched in this state. The pump restarts from that state along with start of
welding.

Idle mode
The machine has an idle mode. The fan is switched off 5 min after the end of the last
welding, or after 5 min of work with decreased speed without welding. The pump is
switched off 3 min after the last welding. When both fan and pump are switched off
the power supply lamp [4] on the front panel is blinking.

ESABMig C420w/C420
The ESABMig C420w/420 is equipped with standard control unit. Welder can
manually select and adjust all welding parameters.
Wire speed (1,9 – 25m/min) is set with knob [12].
The stroke control (2/4 stroke) is selected with switch [13].
Creep start i.e. start with 50% wire speed is toggled ON/OFF with switch [14].
Burn back time is set with knob [15].
The machines C420w/C400 can be fitted with a digital instrument that displays
current and voltage. It incorporates a hold function.

ESABMig C420sw/C420s
ESABMig C420sw/420s control unit enables two ways of welding control:

S the standard control (welder can manually select and adjust all welding
parameters) – switch “SYNERGY” [19] set to OFF
S the synergy control (partly preprogrammed welding parameters) – switch
“SYNERGY” [19] set to any material/gas group

The stroke control (2/4 stroke) or motor inching (only wire feed motor is activated)
is selected with switch [22].
Burn back time is adjusted with knob [21].
Spot welding (turning on and time setting 0,5 – 4s) is activated with knob [13].
For machines C420sw/C420s digital instrument is included as standard.

doce2 – 40 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Standard control mode
When standard control mode is selected lamps [17, 18] are off and only a lower row
of digital display [14] shows wire speed reference (selector [16] shall be in position
”m/min”).
Operator selects the required voltage [2, 3] and he may set wire speed wthin full
range (1,6 – 25m/min) with knob [12].
During welding process the upper row of display shows actual welding voltage or
current, depending on selection with switch [15]. When welding process is stopped,
displayed values are ”frozen” (dimmed display).

Synergy control mode

In synergy control mode, the operator first has to preselect material/gas [19] and
wire diameter [20].
While changing the voltage (with the voltage selectors [2,3]) digital instrument [14]
and lamps [17,18] on the front panel show welding parameters.
Synergy status lamp [17] is green (only in synergy mode) when correct welding
parameters are set, or red when incorrect or not allowed welding parameters are set
(then machine operation is disabled!).
Note: Lamp is also red (in all control modes):

S if during welding (gun trigger pressed) – any voltage selector [2, 3]

is operated, then the operation of the machine is disabled immediately until
the trigger is released,
S when the gun trigger is pressed while turning on the machine with switch [1].
One of the lamps [18] points at recommended current outlet (–) with appropriate
inductance [9,10,11].
Digital display [14] shows values depending on display selectors [15, 16]
and machine status.
Before welding start: the upper display shows expected values of welding current [A]
or voltage [V] (both only in SYNERGY mode); the lower display shows wire speed
reference [m/min] or recommended maximum thickness [mm] of workpiece.
During welding: upper display shows actual welding voltage or current, the lower
display – as above.
After welding stop: the upper display shows last memorised (HOLD) values of
voltage or current (dimmed display).
Wire speed is set by program (stored in the microprocessor) and the knob [12] shall
be set to middle position ”0”. If necessary the operator may correct the preset speed
reference with that knob within +/– 20% of the set value.

doce2 – 41 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 MAINTENANCE
Regular maintenance is important for safe, reliable operation.
Maintenance must be executed by a professional.
Only those persons who have appropriate electrical knowledge (authorised
personnel) may remove the safety plates.
Note!
All guarantee undertakings from the supplier cease to apply if the customer himself
attempts any work in the product during the guarantee period in order to rectify any faults.

Inspection and cleaning

Check regularly that the power source is free from dirt.
The power source should be regularly blown clean using dry compressed air at reduced
pressure. More frequently in dirty environments.
Otherwise the air inlet/outlet may become blocked and cause overheating. To avoid
this you can use an airfilter.

The brake hub

The hub is adjusted when delivered, if
readjustment is required, follow the instructions
below. Adjust the brake hub so that wire is slightly
slack when wire feed stops.

Welding gun
S Cleaning and replacement of the welding gun’s wear parts should take place at
regular intervals in order to achieve trouble–free wire feed. Blow the wire guide
clean regularly and clean the contact tip.

Wire feed unit

Check regularly that the wire feed unit is not clogged with dirt.

S Cleaning and replacement of the wire feed unit mechanism’s worn parts should
take place at regular intervals in order to achieve trouble–free wire feed. Note
that if pre–tensioning is set too hard, this can result in abnormal wear on the
pressure roller, feed roller and wire guide.

doce2 – 42 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 Topping up the coolant
We recommend a 50/50 % mixture of water and ethylene glycol.

ORDERING OF SPARE PARTS

Spare parts may be ordered through your nearest ESAB dealer, see the last page of
this publication.

doce2 – 43 – Edition 030410

Downloaded from www.Manualslib.com manuals search engine

 NOTES

notes – 44 –

Downloaded from www.Manualslib.com manuals search engine

 notes – 45 –

Downloaded from www.Manualslib.com manuals search engine

 ESAB subsidiaries and representative offices

Europe NORWAY Asia/Pacific Representative offices

AUSTRIA AS ESAB BULGARIA
Larvik CHINA
ESAB Ges.m.b.H Shanghai ESAB A/P ESAB Representative Office
Vienna–Liesing Tel: +47 33 12 10 00 Sofia
Fax: +47 33 11 52 03 Shanghai
Tel: +43 1 888 25 11 Tel: +86 21 6539 7124 Tel/Fax: +359 2 974 42 88
Fax: +43 1 888 25 11 85 Fax: +86 21 6543 6622
POLAND EGYPT
BELGIUM ESAB Sp.z.o.o INDIA ESAB Egypt
S.A. ESAB N.V. Warszaw ESAB India Ltd Dokki–Cairo
Brussels Tel: +48 22 813 99 63 Calcutta Tel: +20 2 390 96 69
Tel: +32 2 745 11 00 Fax: +48 22 813 98 81 Tel: +91 33 478 45 17 Fax: +20 2 393 32 13
Fax: +32 2 726 80 05 Fax: +91 33 468 18 80
PORTUGAL ROMANIA
THE CZECH REPUBLIC ESAB Lda INDONESIA ESAB Representative Office
ESAB VAMBERK s.r.o. Lisbon P.T. Esabindo Pratama Bucharest
Prague Tel: +351 1 837 1527 Jakarta Tel/Fax: +40 1 322 36 74
Tel: +420 2 819 40 885 Fax: +351 1 859 1277 Tel: +62 21 460 01 88
Fax: +420 2 819 40 120 Fax: +62 21 461 29 29 RUSSIA–CIS
SLOVAKIA ESAB Representative Office
DENMARK ESAB Slovakia s.r.o. MALAYSIA Moscow
Aktieselskabet ESAB Bratislava ESAB (Malaysia) Snd Bhd Tel: +7 095 937 98 20
Copenhagen–Valby Tel: +421 7 44 88 24 26 Selangor Fax: +7 095 937 95 80
Tel: +45 36 30 01 11 Fax: +421 7 44 88 87 41 Tel: +60 3 703 36 15
Fax: +45 36 30 40 03 Fax: +60 3 703 35 52 ESAB Representative Office
SPAIN St Petersburg
FINLAND ESAB Ibérica S.A. Tel: +7 812 325 43 62
Alcobendas (Madrid) SINGAPORE
ESAB Oy ESAB Singapore Pte Ltd Fax: +7 812 325 66 85
Helsinki Tel: +34 91 623 11 00
Fax: +34 91 661 51 83 Singapore
Tel: +358 9 547 761 Tel: +65 861 43 22
Fax: +358 9 547 77 71 Distributors
SWEDEN Fax: +65 861 31 95
For addresses and phone
FRANCE ESAB Sverige AB ESAB Asia/Pacific Pte Ltd numbers to our distributors in
ESAB France S.A. Gothenburg Singapore other countries, please visit our
Cergy Pontoise Tel: +46 31 50 95 00 Tel: +65 861 74 42 home page
Tel: +33 1 30 75 55 00 Fax: +46 31 50 92 22 Fax: +65 863 08 39
www.esab.com
Fax: +33 1 30 75 55 24 ESAB International AB
Gothenburg SOUTH KOREA
GERMANY Tel: +46 31 50 90 00 ESAB SeAH Corporation
ESAB GmbH Fax: +46 31 50 93 60 Kyung–Nam
Solingen Tel: +82 551 289 81 11
Tel: +49 212 298 0 SWITZERLAND Fax: +82 551 289 88 63
Fax: +49 212 298 204 ESAB AG
Dietikon UNITED ARAB EMIRATES
GREAT BRITAIN Tel: +41 1 741 25 25 ESAB Middle East
ESAB Group (UK) Ltd Fax: +41 1 740 30 55 Dubai
Waltham Cross Tel: +971 4 338 88 29
Tel: +44 1992 76 85 15 North and South America Fax: +971 4 338 87 29
Fax: +44 1992 71 58 03
ARGENTINA
ESAB Automation Ltd CONARCO
Andover Buenos Aires
Tel: +44 1264 33 22 33 Tel: +54 11 4 753 4039
Fax: +44 1264 33 20 74 Fax: +54 11 4 753 6313
BRAZIL
HUNGARY
ESAB S.A.
ESAB Kft
Contagem–MG
Budapest
Tel: +55 31 333 43 33
Tel: +36 1 20 44 182
Fax: +55 31 361 31 51
Fax: +36 1 20 44 186
CANADA
ITALY ESAB Group Canada Inc.
ESAB Saldatura S.p.A. Missisauga, Ontario
Mesero (Mi) Tel: +1 905 670 02 20
Tel: +39 02 97 96 81 Fax: +1 905 670 48 79
Fax: +39 02 97 28 91 81
MEXICO
THE NETHERLANDS ESAB Mexico S.A.
ESAB Nederland B.V. Monterrey
Utrecht Tel: +52 8 350 5959
Tel: +31 30 248 59 22 Fax: +52 8 350 7554
Fax: +31 30 248 52 60
USA
ESAB Welding & Cutting Products
Florence, SC
Tel: +1 843 669 44 11
Fax: +1 843 664 44 58

ESAB AB
SE–695 81 LAXÅ
SWEDEN
Phone +46 584 81 000
Fax +46 584 123 08

www.esab.com

030210
Downloaded from www.Manualslib.com manuals search engine