ESAB Removing and Replacing Capacitor Bank Assembly in the Migmaster 251 Troubleshooting instruction
INSTRUCTIONS for
Removing and Replacing Capacitor Bank Assembly
F-15-479
August, 1998
in the Migmaster 251
P/N 37493
The Capacitor replacement kit includes:
• 1 Capacitor bank assembly
• 2 1/4-20 locking nuts
• 2 1/4-20 nuts
• 7 1/4 flat washer
• 2 1/4-20 x 1 long screws
• 2 3/8-16 nut
• 4 3/8 flat washer
• 2 3/8 split lock washer
• 2 3/8-16 x 1 long screws
Before installing this kit, make sure all primary input power to the
power source is disconnected and/or lock out procedures are in place.
Replacing the capacitor bank assembly is a difficult
and critical procedure. This procedure should only be
undertaken by a skilled technician with the proper tools.
To install kit, proceed as follows:
1. Using the 3/8 wrench remove the four screws retaining the hinged cover.
2. Remove the hinged cover.
3. Using the 3/8 wrench remove the ten screws retaining the large side panel.
4. Remove the side panel.
5. Using the 3/8 wrench or the #3 Robertson screwdriver remove the screw attaching the rear of the
bus-bar to the plastic mounting bracket.
6. Using the 7/16 wrench loosen the locking nuts
holding the heatsink-capacitor assembly to the
plastic mounting bracket.
7. Using the 9/16 wrenches loosen the nuts and bolts
at the rear of the output stud and the top of the
flexible shunt.
8. The heatsink may have sharp edges that can damage wiring insulation, ensure the wires in the vicinity of the heatsink are protected.
9. While supporting the weight of the capacitor assembly and heatsink, remove the four loose bolted
connections.
10. Using a 7/16 wrench remove the nut attaching the
heatsink to the capacitor bus bar.
Tools required:
1. 1 3/8 wrench
2. 1 7/16 open ended wrenches
3. 2 9/16 open ended wrenches
4. 1 #3 Robertson screwdriver
5. Electrical joint compound #2
(Alcoa #2 EJC) - 73585980
11. Carefully remove the capacitor assembly from the
machine.
12. Apply electrical joint compound to the areas around
the three bolt holes of the capacitor bus-bars.
13. Insert the capacitor bus-bar over the bolt in the top
of the heatsink.
14. Align the rear edge of the bus-bar with the heatsink
and attach with a regular nut.
15. Ensure that the bolted connection from the heatsink
to the capacitor bus-bar is tight. This is a high
current electrical connection.
16. Replace the flat washer over the nut.
17. Supporting the weight of the capacitor bank, insert
the bolts from the heatsink into the holes in the
plastic bracket.
18. Install flat washers and locking nuts over the bolts
from the heatsink. Do not fully tighten.
19. Align the top of the bus bar with the back of the
output stud, insert the 3/8 bolt through the output
stud the bus-bar and the copper tab.
20. Assemble the flat washer, lock washer, and 3/8
nut to the bolt.
21. Align the bottom of the bus bar with the inductor
lead and flexible shunt, insert the 3/8 bolt through
the output stud the bus-bar and the copper tab.
22. Assemble the flat washer, lock washer, and 3/8
nut to the bolt.
23. Insert and tighten the 1/4-20 screw through the
plastic bracket to the capacitor bus-bar.
24. Tighten all bolted connections.
25. Insure proper clearances exist between conductors and nearby parts.
26. Insure proper clearances exist between primary
and secondary conductors.
27. Replace the side panel.
28. Using a 3/8 wrench install the ten side panel
mounting screws, do not fully tighten.
29. While supporting the hinged cover in place install
the four cover mounting screws.
30. Tighten the fourteen screws to retain the side and
top covers.
Supplied
F-15-479 8/98
Fig. 1 - Capacitor Bank Assembly for Migmaster 251
Loading...