Lincoln Electric POWER WAVE 355M - Manual (Page 87)

TROUBLESHOOTING AND REPAIR F-41 F-41
POWER WAVE 355M/405M
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AUXILIARY TRANSFORMER TEST (continued)
8. Check the feedback voltage from the current
transducer using a resistive load bank and
with the POWER WAVE 355M/405M in mode
200. Mode 200 is a constant current test
mode. This mode can be accessed using a
wire feeder placed in mode 200 or a laptop
computer and the appropriate software. Apply
the grid load across the output of the POWER
WAVE 355M/405M. Set machine output to
300 amps and enable WELD TERMINALS.
Adjust the grid load to obtain 300 amps on the
external ammeter and check feedback volt-
ages per Table F.6.
A. Pin 1 (lead 801) to Pin 6 (lead 806) should
read 2.4 VDC (machine loaded to 300
amps).
9. If for any reason the machine cannot be
loaded to 300 amps, Table F.6. shows what
feedback voltage is produced at various cur-
rent loads.
10. If the correct supply voltages are applied to
the current transducer, and with the machine
loaded, the feedback voltage is missing or not
correct the current transducer may be faulty.
Before replacing the current transducer, check
the leads and plugs between the control board
(J8) and the current transducer (J90). See The
Wiring Diagram. For access to plug J90 and
the current transducer refer to: Current
Transducer Removal and Replacement
Procedure.
11. Remove input power to the POWER WAVE
355M/405M.
12. Replace the control box top and any cable ties
previously removed.
13. Install the case wraparound cover using the
5/16” nut driver.
TABLE F.6
OUTPUT LOAD CURRENT
EXPECTED TRANSDUCER FEEDBACK
VOLTAGE
300
250
200
150
100
2.4
2.0
1.6
1.2
0.8