DRIVE GP-SWING 1111858 - Caterpillar

(4GM, 6PN),
3512B (8RM, 6WN),
3516B (6HN, 7RN) Generator Set Engines;
3508B (3DM),
3512B (8EM),
3516B (9AN) Marine Auxiliary EnginesReference: Electrical Schematic For 3500B EPG Engines With EMCPII, Form No. SENR1004. Electrical Schematic For 3500B EPG Engines With Switch Gear Conversion, Form No. SENR1005. Electrical Schematic For 3500B EPG Engines For Marine Auxiliary Power Electrical System, Form No. SENR1010.The Woodward Load Share (WLS) module is powered from the generators's potential transformer connections. Therefore, if the generator is not producing electricity the WLS module can not produce a Pulse Width Modulated (PWM) signal to provide a "desired speed signal" to the Engine Control Module (ECM). Without a PWM signal, the engine defaults to low idle RPM speed.
If it is desired to test the engine at a speed other than low idle, when the generator is not providing power to the WLS module, a 9X-9591 Electronic Control Group (speed brick) and a 7C-4471 Potentiometer (10k Ohm, 10 turn) can be temporarily installed. See the References when temporarily disconnecting the WLS module and installing the speed brick.