Model 501K Genset Controller Compact manual engine control module for singleengine generator sets. Designed for straightforward start, run, stop and fault indication using a frontpanel threeposition key switch. Housed in a black ABS enclosure with PCB electronics. Key benefits Simple manual control: threeposition key switch with STOP (O), RUN (I) and START (II) provides intuitive operation for operators. Clear fault indication: individual LEDs for each alarm channel give a firstfault notification and remain latched until reset, helping diagnose issues quickly. Automatic engine protection: on alarm the running relay is deenergized to remove fuel or ignition and stop the engine, reducing risk of further damage. Flexible overspeed protection: optional addon PCB offers adjustable trip between 90 percent and 130 percent of rated speed for 50 Hz or 60 Hz systems. Compact and durable: ABS housing and PCB construction, compact packing dimensions and 1 kg package weight for easy installation and handling. How it works STOP (O): removes power to the module, deenergizes the running relay and disables the alarm output. RUN (I): energizes the module and running relay, activates the engine fuel or ignition system, and starts the protection pause timer. START (II): when held against the spring it supplies the starter output; release after engine starts so the key returns to RUN (I). Alarm handling: low oil pressure, engine temperature, auxiliary shutdown and optional overspeed will deenergize the running relay and activate the alarm output. Each alarm has a dedicated LED. Once an alarm is active, further alarm inputs are ignored until the key is turned to STOP (O) to reset the controller. Protection pause timer: disables the alarm input briefly during engine startup to allow normal start conditions without false trips. Charging monitoring: WL terminal monitoring provides a chargingfailure warning lamp function and supplies alternator excitation current. Technical highlights Model: 501K Control type: manual engine control via threeposition key switch Alarm indications: individual LEDs per channel, latched until reset Alarms monitored: low oil pressure, engine temperature, auxiliary shutdown, optional overspeed Overspeed option: additional PCB required; trip adjustable 90 percent to 130 percent of rated speed; accepts generator Hz signal or engine magnetic pickup (specify pickup type at ordering) Starter operation: momentary START (II) position; RUN (I) holds engine running Charging alternator interface: WL terminal for charging failure indication and excitation supply Enclosure material: ABS with PCB electronics Color: black Packed dimensions: 200 x 180 x 180 mm Package weight: 1000 g Package contents: one 501K controller and one instruction manual Typical applications Backup power systems for commercial or residential properties where simple, reliable manual control and clear fault indication are required. Construction site generator sets that need robust manual start and stop control with immediate fault response. Agricultural and light industrial generators where basic overspeed protection and alternator charging monitoring improve operational reliability. Why choose the 501K controller Provides direct, operatorfriendly manual control with immediate, latched fault indication for quick troubleshooting. Builtin logic removes fuel or ignition automatically on fault, stopping the engine without operator intervention. Optional overspeed module and charging monitor add flexibility to match different generator setups and monitoring needs. Compact ABS construction and simple wiring make installation and replacement straightforward. details Model 501K genset controller supplied with instruction manual. Specify engine magnetic pickup type if overspeed via pickup is required.