Lincoln Electric 11141 Service Manual page 65

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PROCEDURE
1. Remove the input power to the PW355M/405M
machine.
2. Perform the Input Filter Capacitor Discharge
Procedure.
3. Locate and remove plug J21 from the IGBT
Switch Board. See Figure F.3.
4. Using the Volt-Ohmmeter with inductance mea-
suring capabilities check the CT3 current trans-
ducer inductance by checking from J21 pin 1
(#1001) to J21 pin 5 (#1002). Normal induc-
tance is approximately 50mH. +/- 20%. See
Figure F.3. These measurements must be
made at the plug J21 receptacle on the PC
board.
TROUBLESHOOTING AND REPAIR
MAIN SWITCH BOARD TEST (continued)
POWER WAVE
5. Using the Volt-Ohmmeter with inductance mea-
suring capabilities check the CT2 current trans-
ducer inductance by checking from J21 pin 4
(#1010) to J21 pin 8 (#1020). Normal induc-
tance is approximately 50mH. +/- 20%. See
Figure F.3. These measurements must be
made at the plug J21 receptacle on the PC
board.
6. If the inductance reading is not correct replace
the IGBT switch board.
7. When testing is complete replace plug J21 into
the correct receptacle. See Figure F.3.
8. Replace the covers.
® 355M/405M
F-19