Color: HGM420N HGM420N Diesel Generator Set Controller A compact AMF controller designed for reliable automatic mains failure operation and automatic transfer control between mains and generator. The controller combines detailed mains and generator monitoring, engine parameter collection, configurable protections, and flexible control outputs in a durable, easy to mount enclosure. Key benefits Automatic and reliable control of generator start, stop, and automatic transfer switch operation for unattended power systems. Comprehensive monitoring of mains and generator electrical parameters to detect faults such as loss of phase, over voltage, under voltage, over frequency, under frequency, over current, and over power. Clear, multilingual display and rugged user interface for onsite configuration and status checks in harsh environments. Nonvolatile flash storage preserves all settings through power loss, simplifying maintenance and preventing lost configurations. Main features AMF function with automatic mains to generator transfer control and full ATS integration. 132 x 64 backlit display with selectable languages: Chinese, English, Spanish, Turkish, Russian, French. Pushbutton operation with a silicon panel and pushbuttons optimized for and low temperature environments. Hard acrylic screen for improved wear resistance and scratch resistance. Compatible with 3phase 4wire, 3phase 3wire, singlephase 2wire, and 2phase 3wire systems. Nominal voltage 120/240 V, frequency 50/60 Hz. Measures and displays mains and generator parameters: threephase line voltages Uab Ubc Uca, phase voltages Ua Ub Uc, frequency Hz, and phase sequence. Load monitoring: phase currents IA IB IC, splitphase and total active power kW, reactive power kvar, apparent power kVA, power factor PF, accumulated energy kWh, and output percentage with load. Electrical protections for mains: over voltage, under voltage, and loss of phase. Protections for generator: over voltage, under voltage, over frequency, under frequency, over current, and over power. Engine and auxiliary parameter monitoring: coolant temperature WT in C or F, oil pressure OP in kPa psi or bar, fuel level FL percent and remaining fuel in L, engine speed RP in r/min, battery voltage VB in V, charger voltage VD in V, hours counter HC, and start count. Control and protection outputs implemented via relay outputs. Functions include automatic start/stop, ETS Energize To Stop, idle control, preheat, speed raise and speed drop control. All parameters adjustable via front panel, USB, or RS485 using PC interface. Parameters stored in internal flash and retained during power loss. Multiplex inputs: input 3 configurable as auxiliary input or fuel level sensor; input 4 configurable as auxiliary input or other sensor. Supports configurable sensor curves and userdefined sensor calibration for temperature, oil pressure, and fuel level. Enables double temperature, double oil pressure, and double fuel level detection. Multiple crank disconnect options: magnetic pickup, oil pressure, and generator frequency. Emergency start function and flytooth autorecognize function for automatic detection of engine crank teeth. Wide DC supply range DC 8 to 35 V, suitable for various start battery voltages. Digital parameter adjustment for improved reliability over analog potentiometers. Maintenance scheduler by date or running time with configurable actions on timeout (warning or alarm shutdown). Event log up to 99 records, realtime clock, and scheduled generator start/stop (once monthly weekly or daily, on or off load). IP55 waterproof rating with rubberring gasket. Metal fixing clips, modular design, selfextinguishing ABS plastic enclosure, pluggable connection terminals, and embedded mounting for compact, secure installation. Typical applications Standby power systems for commercial buildings: automatic mains failure control and safe transfer of critical loads to the generator. Remote telecom or industrial sites: unattended generator monitoring with scheduled starts, fuel level sensing, engine protection, and wide DC supply compatibility. Construction sites and rental power units: simple front panel configuration, robust enclosure, and relay outputs for integration with ATS and engine governors. Technical highlights Model: HGM420N Display: 132 x 64 backlit Language support: Chinese English Spanish Turkish Russian French Power supply: DC 8 to 35 V Enclosure: modular ABS plastic, IP55 Inputs: multiplexable inputs 3 and 4, configurable sensors Outputs: relay outputs for control and protection Event log: 99 records Data retention: internal flash This controller is intended for integration into generator and mains automatic systems where reliable automatic transfer and comprehensive monitoring are required. It provides rugged construction, flexible inputs and outputs, and straightforward configuration for professional power control installations.