ASCO G7ATB / G962 — Arcing Contact Replacement

Repair & overhaul · Arcing contacts

For the ASCO G7ATB / G962, from the ASCO service manual.

Procedure

1. Remove the movable arcing contact: use needlenose pliers and a screwdriver to remove the spring pin, then remove the flat washer, spring guide, and contact spring.
2. Use a 3/8 in socket wrench to remove two Sems screws from the pigtails, then remove the arcing contact retainer and the movable arcing contact.
3. Remove the stationary arcing contact: use a 3/8 in socket wrench to remove two Sems screws holding the arcing contact and arc chute support plate to the main contact pivot block.
4. Install a new stationary arcing contact and arc chute support plate on the main contact pivot block with two Sems screws; tighten both screws to 66 in-lbs (5.5 ft-lbs).
5. Put two drops of Loctite 222 on the adjustment screw lead threads and install the screw through the new movable arcing contact until it protrudes 1/8 in.
6. Install the movable arcing contact onto the movable main contact, then install the arcing contact spring, spring guide, flat washer, and spring pin.
7. Place the arcing contact retainer between the shunts and pigtails and install two Sems screws through the pigtail lugs, retainer, and shunt lugs; tighten to 66 in-lbs (5.5 ft-lbs).
8. Adjust arcing contacts after all arcing contacts are installed; refer to the contact adjustment procedure.

Source: ASCO service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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