Troubleshooting and repair – Lincoln Electric BULLDOG SVM208-A User Manual
Page 87
Feild Diode Bridge
CAPACITOR AND/OR DIODE BRIDGE
REMOVAL AND REPLACEMENT (continued)
PROCEDURE - FIELD DIODE BRIDGE
REMOVAL AND REPLACEMENT
1. Remove the engine spark plug wire.
2. With the 3/8” nut driver, remove the 8 sheet
metal screws that hold the top cover to the con-
trol box. Remove the top cover.
3. With the 3/8” nut driver and wrench, remove the
6 screws that hold the control panel in place (2
in the front, 2 in the back, 2 in the bottom).
Move the panel aside as far as the leads will
allow.
4. Discharge the field capacitor by connecting the
jumper wire clips on the black and the red wire
terminals on the top of the capacitor. See
Figure F.13 for location. Leave the clips on for
at least 5 seconds, then remove.
5. The field diode bridge (D1) is mounted to the
sheet metal just above the capacitor. See
Figure F.13. Remove it using the phillips head
screw driver.
6. With the needlenose pliers, gently remove the
wires from the field diode bridge. Note lead
locations.
7. Replace the wires to their appropriate locations
on the new diode bridge:
Lead 200 attached to the positive (+) terminal.
Depending on the bridge used, this corner may be
beveled and/or marked with a + sign.
Lead 201 and 201B are piggy-backed on the neg-
ative (–) terminal, which will always be located
diagonally across from the positive (+) terminal.
Leads 9A and 7A are attached to the AC side of
the bridge and are attached to the other two corner
terminals. Either lead can go on either terminal.
8. Mount the field diode bridge using the screw.
Use the slot head screwdriver.
9. Check that the leads are not grounded and for
clearance and tightness.
10. Replace the control panel and tighten the
sheet metal screws with the 5/16” nut driver
and 5/16” wrench.
11. Replace the top cover of the control box and
tighten the sheet metal screws with the 3/8”
nut driver.
TROUBLESHOOTING AND REPAIR
F-39
F-39
BULLDOG® 140
FIGURE F.13 – FIELD DIODE BRIDGE LOCATION
7A
201
(Black)
201B
(Black)
9A
200 (Red)
+
–