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  • IRDH275

    Digital ground fault detector for ungrounded AC/DC systems

    This device meets or exceeds the requirements of NEC 250.21(B) and CEC 10-106(2) for ground detectors in ungrounded AC systems, as well as the new 2014 requirement of NEC 250.167(A) for ungrounded DC systems.

    The IRDH275 monitors for ground faults in ungrounded single-phase AC, three-phase AC, and DC systems by monitoring the system's insulation resistance. It may be connected to systems of up to 793 VAC / 650 VDC. Voltage coupler accessories extend this range. The AMP Plus measuring principle utilized by the IRDH275 meets the requirements of modern power systems, including pure DC systems, systems with rectifiers, and systems with variable frequency drives (VFDs). In systems with high leakage capacitances, the IRDH275 automatically adapts itself to ensure an accurate reading.

    The IRDH275 features a digital display showing the system's insulation resistance'in real-time. All settings are changed via the device's built-in menu. The IRDH275 utilizes an external supply voltage for power, which allows deenergized systems to also be monitored.

    The IRDH275 is a DIN rail mounted type device. For the panel mounted version, please refer to the IRDH375.

  • Key Features: IRDH275

    • Meets requirements for ground detectors in accordance with NEC 250.21(B) and CEC 10-106(2)
    • Ground fault detection for ungrounded AC/DC systems (0...793 VAC, 0...650 VDC)
    • Optional voltage coupler extends range to 7200 VAC / 1760 VDC
    • Two separately adjustable insulation resistance response values, 1 kΩ...10 MΩ
    • Works on pure AC, pure DC, and mixed AC/DC systems, including systems with variable frequency drives (VFDs)
    • Digital display showing readings in real-time
    • Easy-to-use, onboard menu for managing settings
    • Automatic self-test
    • Analog output
    • Built-in test and reset buttons
    • Connections for external test and reset
    • Latching or non-latching operation, selectable
    • Two SPDT contact outputs, normally energized or normally de-energized operation
    • History memory storing up to 300 events ("B" version)
  • Applications: IRDH275

    • AC systems, single- and three-phase
    • Pure DC and mixed AC/DC systems
    • General distribution and control systems requiring fast ground fault location
    • UPS systems and battery systems
    • Systems with variable frequency drives (VFDs)
    • Systems with power conversion components, including rectifiers and inverters
    • Large industrial systems
  • Ordering information: IRDH275

    NameResponse ValueEnhanced temperature and vibration protectionHistory memory for up to 300 recordsCommunication capability0(4) - 20 mA analog outputSupply VoltageOrdering Number
    IRDH275-4351 - 10000 kΩ AC 88 - 264 V (20 - 460 Hz) DC 77 - 286 V B91065100
    IRDH275-4271 - 10000 kΩ DC 19.2 - 72 V B91065104
    IRDH275-4251 - 10000 kΩ DC 10 - 30 V B91065108
    IRDH275B-4351 - 10000 kΩ AC 88 - 264 V (20 - 460 Hz) DC 77 - 286 V B91065101
    IRDH275B-4271 - 10000 kΩ DC 19.2 - 72 V B91065105
    IRDH275B-4251 - 10000 kΩ DC 10 - 30 V B91065109
    IRDH275BW-4351 - 10000 kΩ AC 88 - 264 V (20 - 460 Hz) DC 77 - 286 V B91065101W
    IRDH275BW-4271 - 10000 kΩ DC 19.2 - 72 V B91065105W
    IRDH275BW-4251 - 10000 kΩ DC 10 - 30 V B91065109W
  • Downloads: IRDH275

    Document Name Language Date Download
    Technical Bulletin / Datasheet
    English 08.2013
    Installation Bulletin
    English 08.2013
    User Manual
    English 05.2011
    User Manual
    Modbus TCP Integration
    English 12.2016
    Overview of Products
    English 06.2017
  • Accessories: IRDH275

    Remote Communication Systems

    Ethernet and Modbus/TCP communication gateway for BENDER devices

    NameOrdering Number
    Voltage Couplers

    Voltage coupler for ungrounded DC systems up to 1760 V

    NameOrdering Number
    External Meters

    Analog output meters for BENDER devices

    NameOrdering Number