Generac — Wn 600-2600 Amp: Switch Will Not Retransfer to Utility

Testing & diagnosis · Contactor Assembly (Wn 600-2600 Amp)

From a Generac service manual — check it applies to your exact model before use.

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Procedure

1. Remove front cover.
2. Remove top PCB cover.
3. For testing, note PCB layout (see Figure 4).
4. If switch not tripping to neutral, measure resistance between J1-6 and J1-8. Trip coil resistance should be measured, +/- 7%. If INFINITY, replace trip coil.
5. With switch in generator position, measure resistance between BT1 and J2-6. 0.2 ohms. If INFINITY, replace BTS1 limit switch (071345).
6. Measure resistance between BT2 and J2-5. 0.2 ohms. If INFINITY, replace BTS2 limit switch (071345).
7. Measure resistance between J1-1 and J1-2. Closing coil resistance should be measured.
8. If steps 4 and 5 good and switch not in neutral, push manual trip button to trip to neutral. Measure resistance between A2 and J2-2. 0.2 ohms. If INFINITY, replace LS (074672A).
9. Measure resistance between A1 and J1-1. 0.2 ohms. If INFINITY, measure resistance across AX contacts of AXBX limit switch (071345).
10. If AX contacts closed, measure resistance between NO/Com (upper/lower) contacts on LS (074672A). If INFINITY, replace.
11. If all steps good, replace PCB (082428).

Source: Generac 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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