Troubleshooting Guide - ESAB ESP-150 Manual De Instrucciones

SecTION 5
5.1 TROubleShOOTINg
Check the problem against the symptoms in the following troubleshooting guide . If the cause cannot be
quickly located, shut off the input power, open up the unit, and perform a simple visual inspection of all the
components and wiring . Check for components, bulged or leaking capacitors, or any other sign of damage or
discoloration .
The cause of control malfunctions can also be found by referring to the sequence of operations and electrical
schematic diagram and check out the various components . A volt-ohmmeter will be necessary for some of
these checks .
NOTE: Before checking voltages in the circuit, disconnect the power from the high frequency generator to avoid dam-
aging your voltmeter.
Be sure unit is set up properly for voltage being used and that the gas supplies are adequate .
a. TROubleShOOTINg guIDe
1. unit Inoperative; fan does not run.
a . Check primary disconnect switch to make sure input power is being supplied .
b . Check links on the input terminal board TB to make sure all are connected to the proper input voltage
being used . (See Form 14-376 .)
c . Check for defective power switch (ROS) .
2. No gas flow when torch switch is closed.
a . Unplug torch switch plug and check for proper operation with an ohmmeter connected to pins 1 and 2 of
torch switch plug .
b . Defective interlock switch (ISW) .
c . Check for defective solenoid valves .
d . Plug (P1) may be loose at control board .
e . Defective logic board .
3. Pilot arc-high frequency sparks noted at spark gap but not at the torch.
a . Check spark gap and readjust electrodes if necessary . Replace spark gap electrodes if worn beyond service-
ability .
b . Check with an ohmmeter for continuity between torch nozzle and POS output where torch attaches to
console .
4. No pilot arc-high frequency sparks noted at spark gap and at torch during preflow, but main contactor
does not activate or chatters at end of 2 second preflow time.
a . Check start gas pressure . It must be at least 30 psig .
b . Check cooling gas pressure (PT-26) . It must be at least 50 psig .
c . If using PT-26 torch, check jumper plug between J1-5 and J1-4 on the torch switchplug .
d . Thermal switch in bridge, inductor, or main transformer may be open . Allow unit to cool down .
e . Defective logic board (675369) .
5. No pilot arc - No spark noted in the spark gap.
a . Check to see that pilot arc contactor (PAC) closes . If it does not, and gas flows when torch switch is closed,
replace logic board .
b . If PAC closes, check for proper spark gap setting (0 .040-in .) .
c . Check the 120V input to the high voltage transformer (HFTR) .
d . Check for arcing or carbon tracking around the spark gap .
e . If all of the above check good, HFTR is most likely defective .
6. erratic pilot arc - pilot arc contactor (Pac) chatters.
a . Defective logic board .
b . Power supply may be single phasing . Check main disconnect switch and fuses .
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