Tweco 400 XT Ultra-Cut Plasma Cutting System - Manual (Page 156)

ULTRA-CUT 400 XT
A-�� APPENDIX Manual 0-5275
Code 102 is activated when there is no pilot current after 15 seconds of firing the Arc Starter. Pilot ignition requires the Pilot
board to be enabled, pilot switch (IGBT) turned on and high voltage pulses (HF) from the arc Starter (either the Remote Arc
Starter RAS 1000 XT or GCM 1000 XT or the arc starter built in to the AC 200 XT) applied between the tip and the electrode
of the torch.
Possible Causes for 102 code:
• No HF to the torch due to broken pilot wire connection in the torch leads.
• No HF to the torch due to defective Arc Starter.
• Arc Starter not receiving power.
• Pilot board not enabled.
• Pilot board defective.
• Relay board defective.
• Work lead current sensor defective.
• CCM defective.
Troubleshooting:
1. Determine if the problem is a lack of HF (Arc Starter) or if it’s due to the pilot circuit.
Auto-cut XT Arc Starter (inside main chassis for AC200 XT; in the GCM1000XT for AC300XT) has open spark gap. If the spark
gap is firing it is receiving power. A few early Ultra-Cut XT units were shipped with the RAS1000 Arc Starter. Troubleshoot
them the same as the GCM1000XT below. Most Ultra-Cut XT units now use the RAS1000XT Arc Starter which doesn’t use
a spark gap and is covered in the next section.
Arc starter with Spark Gap (Auto-Cut)
No spark at spark gap
1. Check that spark gap is set for 0.0�2” +/- 0.002”. If gap is too high there may not be enough voltage from T1 to fire the
gap.
2. Check for power to the high frequency (HF) transformer (T2 in AC 200 XT; T1 in GCM1000XT) during the 15 seconds
following prefow (ignition phase). Arc starter power comes through the rear panel circuit breaker CB�, make sure it isn’t
tripped.
a. For the GCM1000XT (AC300XT) 120 VAC from J59-7 & 9 on the power supply rear panel connects to J5�-7 & 9 on
the GCM 1000XT. See diagram below. From J5� on the GCM1000XT it goes directly to the line filter and passes
through the filter to primary of T1. During the ignition phase, check for 120 VAC on the T1 side of the line filter.
b. For AC200XT the HF transformer T2 has insulated Faston (also known as push on , stab-on, spade, etc.) on its primary
wires. Disconnect these and measure for 120 VAC on the harness side during ignition phase.
3. If 120 VAC not present go to step �.
a. If 120 VAC is present and still no spark, T1 (T2 in AC200XT) may be bad. Remove power and measure resistance of
T1 (T2 in AC200XT) primary and secondary. The primary should measure about 3-7 ohms. The secondary about
25-35 K ohms. If either measurement not correct replace T1 (T2 in AC200XT).
b. If T1 (T2 in AC200XT) measures OK, check for shorted capacitors C1-C3 (very unlikely).
�. No 120 VAC to T1 (T2 in AC200XT) primary during the ignition phase (15 seconds following Preflow) check for 120 VAC
into the line filter (GCM1000XT only). If it’s there replace the filter. If 120 VAC isn’t present at the line filter or if this is
an AC 200XT go to step 5 in section Either Arc Starter below.