ESAB Aristotig 405 AC/DC, Service Manual

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7 UNITERROR CODES
If you know what caused the unit control unit to trip, an amber LED comes on to signal a general
fault and an error code is displayed on the front panel. Depending on the indication, you can prob-
ably locate the fault already.
NOTE! If the mains switch is switched off and on in quick succession, the Fault LED will come on
for about 8 seconds. During this time the unit is not functional. As soon as the LED goes off, the
unit becomes functional again.
GENERAL FAULT – NO ERROR CODE (BLANK)
The auxiliary contact 13-14 on mains switch Q1 is not detected as closed. Check connectors, ca-
ble connections and switches. Signal path: A1 detects contact (LED 3 on A1 comes on if contact
is open) and signals the fault to A2 via A8.
ERROR CODE 1: PRIMARY OVERCURRENT
A primary trip is caused if substantially more current flows to the primary of power transformer T3
compared to maximum load. LED2 on A1 comes on as well.
Possible causes:
• Monitoring circuit on module A1 is defective.
• Inter-turn fault in power transformer T3.
• Primary switch A5, A12 or A4, A11 defective.
• Defect in secondary rectifier AP10, AP11 or its protective circuit.
• Transformer shunt T2 defective, or cable connection to inverter control board defective.
• Defect in current regulation circuit of inverter control board A8.
• Module A1 defective.
• Loose contact on T1, T5 causes high voltage arc-over which trips the primary.
ERROR CODE 2: MAINS UNDERVOLTAGE
For good welding quality, the mains voltage should be in the following range: voltage between two
conductors: 400 V ± 10%.
The unit is typically switched off at about 300 V and remains off as long as the undervoltage per-
sists.
On 3-phase AC systems, if only undervoltage is signalled in the upper power range, there may be
one phase missing.
ERROR CODE 3: MAINS OVERVOLTAGE
Use a suitable instrument to check the actual value of the mains voltage while the unit displays
overvoltage.
Regular or continuous operation of the unit at mains overvoltage may cause failure, first on elec-
trolytic capacitors (C1 to C4) and on the starter (A7).
For good welding quality, the mains voltage should be in the following range: voltage between two
conductors: 400 V ± 10 %.
The unit is typically tripped at about 460 V (AC) overvoltage. If the error signalling proves to be
wrong, renew A1.