Troubleshooting & repair, Snubber resistor test (cont.) – Lincoln Electric INVERTEC V300-PRO SVM105-B User Manual
Page 60
V300-PRO
TROUBLESHOOTING & REPAIR
1. Turn main Power off.
2. Perform Input Filter Capacitor Discharge proce-
dure.
3. Remove leads 401,402 403 & 404 from theSwitch
Boards.
4. Test for 25 ohms resistance from lead 401 to termi-
nal 12 on Switch Board.
a. If 25 ohms is measured, Resistor R4 is OK.
b. If 30 ohms or more is measured, Resistor R4 is
faulty and must be replaced.
c. If 20 ohms or less is measured, Resistor R4 is
faulty and must be replaced.
5. Repeat same procedures to test R5, R6, and R7 per
Table F.4.
F-30
F-30
SNUBBER RESISTOR TEST (cont.)
L8604-1
L8604-1
SWITCH
SWITCH
9R
W
12
WR
401/
403
1/
8
4/
5
402/
404
FIGURE F.9 - SNUBBER RESISTOR TEST POINTS
Check
Test Result
Conclusion
Next Test Step
Repair Action
Lead 401 to
25 ohms
OK
Continue
Terminal 12
>30 ohms
R4 open
Replace R4
<20 ohms
R4 faulty
Lead 402 to
25 ohms
OK
Continue
Terminal 9
>30 ohms
R5 open
Replace R5
<20 ohms
R5 faulty
Lead 403 to
25 ohms
OK
Continue
Terminal 12
>30 ohms
R6 open
Replace R6
<20 ohms
R6 faulty
Lead 404 to
25 ohms
OK
Continue
Terminal 9
>30 ohms
R7 open
Replace R7
<20 ohms
R7 faulty
TABLE F.4 SNUBBER RESISTORS TEST