Description

BENDER IRDH275B-427 ISOMETER® Insulation Monitoring Device Product Description

Technical Specifications

• Product Model: IRDH275B-427
• Brand: BENDER (Germany, Professional IT System Insulation Monitor)
• Warranty: One Year
• Input Supply Voltage: AC 19.2–55 V / DC 19.2–72 V narrow-range auxiliary power, power consumption ≤14 VA
• Operating Temperature: -20°C to +60°C (-4°F to 140°F)
• Storage Temperature: -40°C to 85°C (-40°F to 185°F)
• Response Time: Fast insulation fault judgment with automatic adaptation to high system stray capacitance
• Protection Class: IP20 housing, EMC surge/ESD suppression, fully compliant with IEC 61557-8 safety standard
• Accuracy Class: High-precision AMPPlus patented measurement algorithm, adjustable alarm threshold from 1 kΩ to 10 MΩ for two-stage pre-alarm and main alarm
• Applicable System Frequency: 0.1–460 Hz, compatible with AC, DC and mixed AC/DC IT ungrounded power networks
• Rated System Voltage: AC 0–793 V three-phase IT system, DC 0–650 V ungrounded DC power supply
• Communication Interface: RS485 BMS bus protocol, integrated Ethernet port with Modbus TCP and embedded web server, 4–20mA analog signal output
• Supported Protocols: Bender proprietary BMS, Modbus RTU, Modbus TCP, remote web access diagnosis
• Overload Capacity: Built-in periodic self-test function, two groups of SPDT relay alarm contacts, 300-event fault history storage, reverse power connection protection
• Dimensions: Standard DIN rail mounted yellow industrial plastic enclosure with front LCD graphical display and operation buttons
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Product Overview

The IRDH275B-427 is a premium ISOMETER® insulation monitoring module developed by BENDER, specially designed for continuous insulation resistance supervision on unearthed IT power distribution systems. Adopting the exclusive AMPPlus measuring technology, it perfectly overcomes measurement interference caused by large distributed capacitance on frequency converters, rectifiers and complex AC-DC hybrid circuits, delivering stable and accurate leakage detection results. It supports independent parameter setting for two alarm levels to realize early warning of insulation degradation and urgent fault alert, effectively preventing electric shock hazards and short-circuit fire risks triggered by single-point grounding faults in isolated power grids. The B-version upgrade expands 300 sets of fault event recording capacity, which greatly facilitates post-failure tracing and equipment maintenance.