Tweco 400 MST Arc Master - Manual (Page 42)

400MST
9
ADVANCED TROUBLESHOOTING
9 – 5
1.2.2 E02 "Over-Temperature at the
secondary side"
Cause
Occurs when an over-temperature condition of the
secondary IGBT and diode are detected.
Verification/Remedy
a) Unit may be in thermal shutdown mode.
 Review the rated duty cycle of the unit per
section 2.6. Exceeding the duty cycle
can damage the unit and void the warranty.
Refer also to section 2.7 for addi-
tional information.
b) Verify the ventilating condition.
 Maintain a clear and unobstructed distance
of more than 12 in. in the front and more that
20 in. in the rear of the unit for ventilation pur-
poses.
 Verify and maintain clean, dust free, front and
rear airflow paths. Cleaning and removing
dust from the front and rear panels once
every six months in a normal working envi-
ronment is recommended. Extremely dusty
environments will require more frequent
cleanings.
c) Verify the operation of the cooling fan, FAN1,
and replace it if necessary.
 Verify the condition of FAN1. Verify that there
are no broken or cracked fan blades and that
FAN1 is not producing any abnormal sounds.
 If broken or cracked FAN1 blades or abnor-
mal sounds are emanating from FAN1,
replace FAN1.
 Refer to section 9.2.4.19 for the replacement
of FAN1.
 Refer to section 9.1.4.4 for additional FAN1
tests.
 Verify the operation of the cooling fan and
replace it if the condition of FAN1 is inactive.
Follow the instruction in section 9.1.4.4.
d) Replace PCB3 (WK-5548).
 Refer to section 9.2.4.3 for the replacement
of PCB3.
1.2.3 E03 "Primary Over-Current Failure"
Cause
Occurs when excessive current is detected flow-
ing into the primary side of the main transformer.
Verification/Remedy
a) Confirm the operation of the machine within
the rated specification.
 Refer to the specification data sheet in Sec-
tion 2.6.
b) Verify the secondary diode (D2, D3, D4, D5,)
 Refer to section 9.1.4.6 for the test and
replacement of D2 and to section 9.2.4.24 for
D3, D4, D5.
c) Replace the Hall CT, HCT1.
NOTE
Pay special attention to installed direction of HCT1.
The Hall CT will not function properly if installed in
the incorrect direction.
 Refer to section 9.2.4.22 for the replacement of
HCT1.
1.2.4 E11 "High Input Voltage Failure"
Cause
Occurs when the input voltage is more than
approximately 275VAC (at input voltage 230V) or
520VAC (at input voltage 460V) (=1/1.41 of the
maximum value of the sinusoidal wave).
Verification/Remedy
a) Verify input voltage.
 Follow the instruction in section 9.1.4.2.
b) Replace PCB4 (WK-4819).
 If the voltage and current available is deter-
mined to be sufficient, replace PCB4.
 Refer to section 9.2.4.4 for the replacement
of PCB4.