Bender IRDH275-435 Ground Fault Detector, 77-286V AC, 1kΩ-10MΩ

The Bender IRDH275-435 is a precision ground fault detector designed for industrial insulation monitoring applications. This DIN-rail mounted device monitors 1Ø AC, 3Ø AC, and DC systems, measuring insulation resistance across a range of 1 kΩ to 10 MΩ. The IRDH275-435 operates on a supply voltage of 77-286 V AC (42-460 Hz) or 88-264 V DC. The device features dual alarm relays (K1 and K2) with SPDT contacts configurable for normally energized or deenergized operation. Analog output options include standard 0-400 μA or optional 0/4-20 mA for B-models. Communication is achieved via RS-485 interface supporting proprietary 2-way protocol. The unit supports external TEST and RESET terminals, STANDBY function for stopping measurements, and features a front panel display with LED indicators for Alarm 1, Alarm 2, and Error states. Includes menu-driven setup for advanced configuration including ISO ADVANCED settings for use with voltage couplers (AGH150W-4, AGH204S-4, AGH520S) for systems up to 7200 V.