Cummins/Onan — Reactors Testing - Method D (Ohmmeter)
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
- Select resistance range on meter to resistance specified in Table 3 for given rectifier model.
- Isolate one gate winding by disconnecting either end of gate winding G1-G2; e.g., disconnect G1 at E2.
- Measure resistance in gate winding across G1-G2.
- Isolate control winding by disconnecting either lead C1 or C2 from terminal strip. Measure resistance across C1-C2.
- Connect one meter lead to disconnected gate winding lead and other to disconnected control winding lead; check continuity.
- Good if resistance within ±20 percent of Table 3 value and no continuity between control and gate windings.
- Defective if open circuit in gate or control winding or continuity between windings; replace reactor.
Tools required
- ohmmeter (multimeter) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- resistance within ±20 percent of Table 3 value
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.