Cummins/Onan — Reactors A and B Testing - Method E (120-volt AC Tester)

Testing & diagnosis

From a Cummins/Onan service manual covering: 02SX1N1A, 04SX1N, 04SX1N1A, 04SX1N1B, 04SX1N2B, 04SX1N3B, 04SX1N4B, 06SX1N, 06SX1N1A, 06SX1N1B, 06SX1N2B, 06SX1N3B…. Check it applies to your exact model before use.

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Procedure

1. Remove exciter from generator.
2. Make certain no part of Magneciter is grounded.
3. Isolate gate winding by disconnecting one lead from its point of connection.
4. Isolate control winding by disconnecting both leads C1 and C2 from their points of connection.
5. Connect one test lead to G1 and other to G2 and observe light bulb.
6. With leads still connected to gate winding, short across leads C1 and C2 and observe bulb.
7. Connect one test lead to control winding lead and other to one gate winding lead and observe bulb.
8. Good if bulb dark for steps 5 and 7 but bright for step 6.
9. Defective if bulb low intensity for step 5, lights for step 7, or fails step 6; replacement required.

Source: Cummins/Onan 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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