Troubleshooting & repair – Lincoln Electric WELDANPOWER SVM 113-A User Manual
Page 57
OUTPUT RECTIFIER BRIDGE TEST
(continued)
FIGURE F.4 - OUTPUT RECTIFIER BRIDGE
W2
W1
204
Strap
203
TEST PROCEDURE
1. Conduct this test with the gasoline engine
OFF.
2. Remove the spark plug wire to prevent
accidental engine kickback or starting.
3. With the 5/16" nut driver, remove the 8
sheet metal screws that hold the top cover
to the control box. Remove the top cover.
4. Locate the output rectifier bridge.
5. With the 7/16" wrench, remove the nuts
and washers that hold the four diode pigtail
leads and the heavy current carrying leads
to the studs located at the front of the rec-
tifier bridge assembly. Note lead place-
ment for reassembly. See Figure F.4.
6. Electrically isolate the diode pigtails.
7. With the volt/ohmmeter or diode tester,
check the resistance of each of the four
diodes from their pigtail leads to their
respective heat sinks. Alternate placement
of the test probes. Resistance should be
high in one direction and low in the other.
8. Replace any shorted or open diodes.
9. Reassemble the heavy current carrying
leads and pigtails to their respective
studs. The proper fastener sequence is:
pigtail - lead - flat washer - lock washer -
nut.
10. Replace the top cover on the control box.
Tighten the 8 sheet metal screws with the
5/16" nut driver.
TROUBLESHOOTING & REPAIR
F-19
F-19
WELDANPOWER 125