{"product_id":"st420hf-series-combined-electrical-fire-monitoring-detector-residual-current-temperature-protection","title":"ST420HF Series Combined Electrical Fire Monitoring Detector | Residual Current \u0026 Temperature Protection","description":"\u003cp\u003eThe ST420HF is a combined electrical fire monitoring detector designed for TT and TN systems up to 690V, developed in accordance with Chinese national standards for electrical fire monitoring systems. It monitors residual current and temperature parameters in distribution circuits to detect and prevent electrical fire hazards before they occur.\u003c\/p\u003e\u003cp\u003eSuitable for large shopping malls, residential complexes, industrial and mining enterprises, office buildings, hotels, and any location where electrical fire risk management is required.\u003c\/p\u003e\u003ch2\u003eSystem Overview\u003c\/h2\u003e\u003cp\u003eThe ST series electrical fire monitoring system consists of:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eST series monitoring equipment\u003c\/strong\u003e (e.g. ST2000FB \/ ST2000FB-H) — communicates with field detectors via RS485 bus, receives and forwards data, triggers alarms, and stores fault records\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eST series detectors\u003c\/strong\u003e (including ST420HF) — monitors residual current and temperature at distribution circuit level\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eKey Features\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRS485 bus communication between monitoring equipment and detectors\u003c\/li\u003e\n\u003cli\u003eReal-time monitoring and LCD display of residual current and temperature from all connected detectors\u003c\/li\u003e\n\u003cli\u003eAudible and visual alarm for residual current fault, over-temperature, power failure, and communication fault\u003c\/li\u003e\n\u003cli\u003eData storage, query, and alarm control signal output\u003c\/li\u003e\n\u003cli\u003eDual power supply with automatic main\/backup switchover; LED status indicators on panel\u003c\/li\u003e\n\u003cli\u003eSelf-diagnostic function on startup\u003c\/li\u003e\n\u003cli\u003e8-channel relay output for controlling protected circuits or external devices\u003c\/li\u003e\n\u003cli\u003eResidual current protection + temperature protection in a single unit\u003c\/li\u003e\n\u003cli\u003eWiFi wireless data upload\/download\u003c\/li\u003e\n\u003cli\u003e2.8-inch color display\u003c\/li\u003e\n\u003cli\u003eLine protection function included\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eST420HF Specifications\u003c\/h2\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFunction\u003c\/th\u003e\n\u003cth\u003eST420HF\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eResidual current protection\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature protection\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResidual current measurement\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature measurement\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAlarm records\u003c\/td\u003e\n\u003ctd\u003e16 records\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDigital input (DI)\u003c\/td\u003e\n\u003ctd\u003e8 channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRelay output (DO)\u003c\/td\u003e\n\u003ctd\u003e4 channels\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAnalog output (AO)\u003c\/td\u003e\n\u003ctd\u003e+1 or +2 channels (optional)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResidual current input\u003c\/td\u003e\n\u003ctd\u003e1 channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature input (T)\u003c\/td\u003e\n\u003ctd\u003e1 channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModbus-RTU\u003c\/td\u003e\n\u003ctd\u003e1 channel + 1 channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLine protection function\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWiFi\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDisplay\u003c\/td\u003e\n\u003ctd\u003e2.8-inch color screen\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProgrammable functions\u003c\/td\u003e\n\u003ctd\u003e✓ Standard\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eDimensions\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eMain unit: 103 × 64.5 × 122.0 mm\u003c\/li\u003e\n\u003cli\u003ePanel cutout: 87.5 × 51.0 mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eStandards Compliance\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eGB 14287.1 — Electrical Fire Monitoring Systems, Part 1: Monitoring Equipment\u003c\/li\u003e\n\u003cli\u003eGB 14287.2 — Part 2: Residual Current Electrical Fire Monitoring Detectors\u003c\/li\u003e\n\u003cli\u003eGB 14287.3 — Part 3: Temperature-Sensing Electrical Fire Monitoring Detectors\u003c\/li\u003e\n\u003cli\u003eGB 50016 — Code for Fire Protection Design of Buildings\u003c\/li\u003e\n\u003cli\u003eGB 50116 — Code for Design of Automatic Fire Alarm Systems\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Wanlong Electric","offers":[{"title":"Default Title","offer_id":44140650561602,"sku":null,"price":260.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0688\/1221\/0242\/files\/ST420F-T1_-3.webp?v=1784272704","url":"https:\/\/wanlongelectric.com\/products\/st420hf-series-combined-electrical-fire-monitoring-detector-residual-current-temperature-protection","provider":"Wan Long Electric Group Co., Ltd.","version":"1.0","type":"link"}