Power Source Problems - Thermal Arc ARCMASTER 200 TS Service Manual

3

Power Source Problems

Description
1 The welding arc cannot
be established.
2 Maximum output
welding current can not
be achieved with
nominal Mains supply
voltage.
3 Welding current
reduces when welding.
4 No gas flow when the
torch trigger switch is
depressed.
5 Gas flow won't shut off. A Weld Mode (STD, SLOPE, REPEAT or
6 The TIG electrode has
been contaminated due
to the gas flow shutting
off before the
programmed POST-
FLOW time has elapse.
Possible Cause
A The Primary supply voltage has not been
switched ON.
B The Welding Power Source switch is
switched OFF.
C Loose connections internally.
Defective control circuit.
Loose welding cable connections.
A
Incorrect welding cable size.
B
Improper input connections.
C
D Poor electrode condition.
Wrong welding polarity.
E
A Gas hose is cut.
B Gas passage contains impurities.
C Gas regulator turned off.
D Torch trigger switch lead is disconnected
or switch/cable is faulty.
SPOT) was changed before POST-
FLOW gas time had finished.
B Gas valve is faulty.
C Gas valve jammed open.
D POST-FLOW control is set to 60 sec.
The Weld Process Mode (STICK, HF TIG or
LIFT TIG) was changed before POST-FLOW
gas time had finished.
Table 8-3: Power Source Problems
200TS
A Switch ON the Primary supply voltage.
B Switch ON the Welding Power Source.
C Have an Accredited Thermal Arc Service
Agent repair the connection.
Have an Accredited Thermal Arc Service
Agent inspect then repair the welder.
Tighten all welding cable
A
connections.
Use proper size and type of cable.
B
Refer to Section 2.05 Electrical Input
C
Requirements.
D Replace electrode.
Verify output torch connections.
E
A Replace gas hose.
B Disconnect gas hose from the rear of
Power Source then raise gas pressure
and blow out impurities.
C Turn gas regulator on.
D Reconnect lead or repair faulty switch/
cable.
A Strike an arc to complete the weld cycle.
OR Switch machine off then on to reset
solenoid valve sequence.
B Have an Accredited Thermal Arc Service
Agent replace gas valve.
C Have an Accredited Thermal Arc Service
Agent repair or replace gas valve.
D Reduce POST-FLOW time.
Do not change Weld Process Mode before
the POST-FLOW gas time had finished.
8 – 4
8
BASIC TROUBLESHOOTING
Remedy