Lincoln Electric INVERTEC V275-S Service Manual page 64

F-34
OUTPUT CURRENT SHUNT TEST (continued)
TEST PROCEDURE
1. Remove input power to the V275-S.
2. Using the 5/16" nut driver, remove the case
wraparound cover.
3. Perform the Input Capacitor Discharge
Procedure.
4. Locate plug J2 on the control board. Do not
remove the plug from the P.C. board. See
Figure F.14.
5. Locate the output shunt. See Figure F.13.
6. Apply the correct input voltage to the V275-S.
7. Apply a 200 amp resistance grid load to the
output terminals.
8. Verify the 200 amp load with the external DC
ammeter.
TROUBLESHOOTING AND REPAIR
FIGURE F.13 - Output Current Shunt Location
380V
208-230V
9. Carefully measure the voltage drop across the
shunt. With a 200 amp load the voltage across
the output shunt should be 100MV.
10. Reduce the 200 amp load to 100 amps. The
voltage across the output shunt should be
50MV.
11. This voltage should also be present at plug J4
pin 2 (lead W221+) to plug J4 pin 1
R222-). See Figure F.15.
12. Make sure the connections are tight and the
leads are in the correct pin locations in plug J4.
See Figure F.14. See the Wiring Diagram.
13. If the voltages across the output shunt are not
correct the output shunt may be faulty.
14. Remove the input power to the V275-S
machine.
15. Replace the case wraparound cover.
V275-S
F-34
Output
Shunt
(lead