ESAB 100i Service Manual page 79

Arc starter without Spark Gap (ISeries)
1. Check for power to the RAS's Ignition Module during the 15 seconds following preflow (ignition phase).
Arc starter power comes through the rear panel circuit breaker CB4, make sure it isn't tripped.
a. During the ignition phase, measure for 120 VAC at the input terminals marked 120 VAC on the Ignition
module, a gray rectangular box with screw terminals on one side.
WARNING
Do not let the meter probes (or your hands) come in contact with the other terminals
marked Hb and Ho or the other end of the wires connected to them. These can have
10,000 volt pulses which can cause physical harm and will damage your meter.
2. If 120 VAC is not present go to step 3.
a. If 120 VAC is present and still no spark, the Ignition Module may be bad.
3. 120 VAC to the remote Arc Starter comes from J59-7 & 9 on the power supply rear panel and connects to
J58-7 & 9 on the RAS1000XT. Remove the cable from J59 and during the ignition phase measure for 120 VAC
between pins 7 & 9.
a. If 120 VAC is present problem is in the cable to the RAS or the J58 connector and internal harness in the
Arc Starter.
b. If 120 VAC is present proceed to the next step.
4. 120 VAC to J59 comes from the relay board J8-3 with return on pin 11. On the Relay board, RF ON LED,
D23, should be on during the igniting phase. If it is not skip to the next step.
a. If D23 is on and there is not 120 VAC at J8-3 & 11 then the Relay board is bad.
Either Arc Starter
5. /RAS ON signal not on. CCM sends active low signal " /RAS ON" over the 40 pin ribbon cable on pin
16 to the Relay & Interface board. On the relay board RAS Control relay (K2) closes (RF ON LED, D23 on)
sending 120 VAC to J8-3 with return on J8-11. From here it either goes to the HF transformer T2 (AC200XT)
or to J59 as described above.
a. Measure the signal "/RAS ON" on pin 16 of the 40 pin ribbon cable relative to TP1 on either the CCM
I/O board or the Relay board. If it is low (less than 1V) skip to step 6. Otherwise continue this step.
NOTE!
If the CCM thinks there is already a pilot it would not enable the HF. Pilot board has a current sensor
that sends a differential analog pilot current level signal to the Relay board which in turn passes that
signal to the CCM. On the Relay board D11 LED "Pilot Current Detected" or just "PILOT" lights if it
sees a signal from the pilot board.
Reasons why RAS Control relay would not close:
6. Pilot current flowing. There actually is pilot current flowing somewhere. Unlikely as it would normally set
the 208 fault but we have to rule it out.
a. Disconnect J41 on the Pilot board, if HF still doesn't fire and the Relay board Pilot LED, D11, is still
on, it's due to a fault in the detection circuits.
7. Faulty detection circuit. There isn't any pilot current but a fault in the circuits measuring pilot current is
indicating there is current.
a. Measure between pins 8 (-) and 9 (+) on the Pilot ribbon cable from Relay board J3 to Pilot board J42. If
there is no pilot current it should be zero. Anything else indicates the Pilot board current sensor is faulty
causing the Relay board D11 to be on. Replace the Pilot board assembly.
Manual 0560956456
iSERIES 100 /200 /300 /400
APPENDIX A-59