Lincoln Electric SVM 113-A service manual Output Rectifier Bridge Removal and Replacement

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F-48 F-48

TROUBLESHOOTING & REPAIR

OUTPUT RECTIFIER BRIDGE REMOVAL AND REPLACEMENT (continued)

FIGURE F.20 - OUTPUT RECTIFIER CONNECTIONS

203

W2

W1

204

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PROCEDURE

1.Remove the engine spark plug wire to pre- vent accidental kickback or starting.

2.With the 5/16" nut driver, remove the 8 sheet metal screws from the case top.

3.With the 7/16" wrench, remove the heavy leads W1 and W2 from the stud terminals. You do not have to remove the diode pig- tails from the terminals. See Figure F.20.

4.With the 7/16" wrench, remove the "N" negative lead and the #204 lead from the negative heat sink. Note placement of the leads for reassembly.

5.With the 7/16" wrench, remove the choke lead and the #203 lead from the positive heat sink. Note placement of the leads for reassembly.

6.With the 3/8" wrench, remove the four mounting screws holding the output rectifi- er bridge assembly to the choke. Note the placement of the insulators. When you reassemble the output rectifier bridge, the heat sink assembly MUST be electrically isolated from case ground.

7.Carefully lift up and remove the output rec- tifier bridge assembly.

8.Reassembly: Refer to the Wiring Diagram for proper connections to the positive and negative sides of the rectifier assembly. The two sides of the bridge are marked + and –, respectively.

NOTE: Use Dow Corning 340 on all aluminum electrical connection surfaces. If you replace individual diodes, use Dow Corning 340 on all mating surfaces between the diodes and the heatsink.

9.Install the rectifier bridge assembly by tilt- ing it down into its position above the choke assembly. Be sure that the positive

(+) side of the bridge, as marked, is on the right side of the machine, looking from the case front.

10.With the 3/8" wrench and slot head screw driver, install the four mounting screws (two on each side). Note the placement of the nylon insulators. These must be in place when you install the rectifier bridge assembly in order to electrically insulate the bridge from the choke lam- ination assembly.

WELDANPOWER 125