Kohler — Separately Excite - Static Models (RY)
Testing & diagnosis · Generator field (rotor)
From a Kohler service manual covering: 10/15RMOY, 15/17.5ROY, 15RMY, 22.5-47.5ROZ, 22.5/32.5RZ. Check it applies to your exact model before use.
Applies to: Kohler 15RMY
Before you start
- HIGH OUTPUT VOLTAGE DURING TESTS MAY ENDANGER HUMAN LIFE OR DAMAGE EQUIPMENT! Disconnect generator from load when troubleshooting.
Procedure
- Disconnect and insulate L1, L2, L3, V7, V8, V9, VO and V4.
- Connect brush leads in series with a 12-volt battery and DC ammeter as shown in Figure 3-2.
- Record ammeter reading.
- Start unit and observe ammeter; reading should remain the same.
- If current increases considerably, a running short in the rotor has been detected. If current drops to zero, an open rotor is indicated.
- If tests show shorted or open rotor - replace.
- While unit is running check L1, L2, L3, V7, V8, V9, VO and V4 for AC output.
- If any winding shows no output - repair or replace stator. If output reading is correct, problem is in the Automatic Voltage Regulation (AVR) circuit.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Kohler 15RMY →
Source: Kohler 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.