Thermal Arc 185 AC, Service Manual

Page: 44 / 122

8-6 May 22, 2006
ARCMASTER 185 ACDC 200 ACDC
8.05 Power Source Problems
Description Possible Cause Remedy
1 The welding arc cannot
be established
A
B
The Primary supply voltage has not
been switched ON.
The Welding Power Source switch is
switched OFF.
A
B
Switch ON the Primary supply
voltage.
Switch ON the Welding Power
Source.
C Loose connections internally. C Have an Accredited Thermal Arc
Service Agent repair the connection.
2 Maximum output
welding current can not
be achieved with
nominal Mains supply
voltage.
Defective control circuit Have an Accredited Thermal Arc
Service Agent inspect then repair the
welder.
3 Welding current
reduces when welding
Poor work lead connection to the
work piece. Ensure that the work lead has a
positive electrical connection to the
work piece.
4 No gas flow when the
torch trigger switch is
depressed.
A
B Gas hose is cut.
Gas passage contains impurities. A
B Replace gas hose.
Disconnect gas hose from the rear of
Power Source then raise gas
pressure and blow out impurities.
C Gas regulator turned off. C Turn gas regulator on.
D Torch trigger switch lead is
disconnected or switch/cable is
faulty.
D Reconnect lead or repair faulty
switch/cable.
5 Gas flow won’t shut off A Weld Mode ( STD, SLOPE, REPEAT
or
SPOT) was changed before
POST-FLOW gas time had finished.
A Strike an arc to complete the weld
cycle.
OR
Switch machine off then on to reset
solenoid valve sequence.
B Gas valve is faulty. B Have an Accredited Thermal Arc
Service Agent replace gas valve.
C Gas valve jammed open. C Have an Accredited Thermal Arc
Service Agent repair or replace gas
valve.
D
POST-FLOW control is set to 60 sec. D Reduce POST-FLOW time.
6 The TIG electrode has
been contaminated due
to the gas flow shutting
off before the pro-
grammed
POST-FLOW
time has elapsed
The Weld Process Mode (STICK, HF
TIG or LIFT TIG) was changed
before
POST-FLOW gas time had
finished.
Do not change Weld Process Mode
before the
POST-FLOW gas time had
finished.
Table 8-3: Power Source pROBLEMS