ESAB 100i Service Manual page 86

iSERIES 100 /200 /300 /400
of IM#1 are enabled and CCM measures the power supply output voltage between negative (Torch) to positive
(Work) at the output terminals. If this is less than a set value during preflow or if at any time during piloting
or cutting it drops to below that value for a short time, the inverters are shut off and code 205 is set. 205 will
almost always be indicated as an "L", not an "E" fault because as soon as it's detected the inverters are shut off
and so no longer have the fault of low output voltage. Currently the low voltage value is -60VDC.
Causes of 205 code can include shorts outside the plasma power supply, shorts inside the plasma power supply
and measurement errors.
a. Short external to the plasma power supply:
• Cable pinched in or exiting the power track
• Short inside the Arc Starter such as a wire coming loose and grounding to the chassis.
• Short inside the torch mounting tube.
• Trouble shoot for external negative lead shorts by removing the lead from the rear of the power supply
and try to start. It won't start but if you get the same 205 code the problem is inside the unit.
b. Short inside the supply:
• All the inverters outputs except that of IM1A are in parallel. If any inverter's output is shorted it will
appear as a short across the power supply output.
Troubleshoot by removing all (or one at a time) of the inverter output connectors except those on IM1A.
Then apply Start to the unit. If it starts now one of the other inverters had shorted output. To find the
defective one reconnect one at a time until the fault reappears.
206 Not used. Reserved codes from the earlier product.
207 Unexpected Current in the Work Lead.
HCT1, a Hall Effect current sensor on the positive (work buss bar) measures the work lead current. Inverter
section 1A is enabled during preflow time but there should be no current in the work lead before the pilot is
ignited and before the arc is transferred to the work. If current greater than 8A is detected before or during
preflow something is wrong.
1. 207 code before START applied:
• Defective work current sensor, HCT1.
• Defective Relay PCB
• Defective CCM
Defective Sensor
• The work current sensor, HCT1, receives power, +15VDC and -15VDC from the Relay PCB. Both must
be present for the sensor to work properly. Measure between Relay PCB TP1 (or J1-4) to J1-1 for +15VDC
and to J1-2 for -15VDC.
• If either + or – 15VDC not present remove the J1 connector and repeat the measurement at J1-1 & 2 on the
Relay board. If the voltage is now present the sensor is defective or shorted (the harness may be shorted).
If voltages still not present, the Relay board is defective.
Relay PCB
• Relay board LED D12, Work Current Detected, will light if the current sensor signal exceeds 0.05V. If
D12 is on, measure the sensor output signal at J1-3 with signal common on J1-1. This signal should be
0V +/- 0.04VDC. If greater than +/- 0.04VDC with no work lead current, the sensor is defective. If the
signal voltage is within the limits and D12 is on, then the Relay board is defective.
• If D12 is not on and the 207 code is still active, either the Relay board or the CCM is defective.
CCM or ribbon cable
• The work current signal leaving the relay board is on the 40 pin ribbon cable (Relay J4 to CCM J23) pins
27 (-) & 28 (+). If the voltage here exceeds 0.1VDC with no work current the Relay board is likely defec-
A-66 APPENDIX Manual 0560956456