1. Product Overview
The BENDER IRDH275BM-727 is a high-precision insulation monitoring device (ISOMETER®) designed for ungrounded systems (IT systems). It continuously measures the insulation resistance between live conductors and earth, ensuring electrical safety in critical facilities. The device is suitable for AC, AC/DC, and DC IT systems.
2. Key Features
· AMPPlus patented measurement technology – Accurately measures insulation resistance even in modern power systems containing rectifiers and inverters. Automatically adapts to system leakage capacitance and optimizes measurement time.
· Two independent adjustable alarm thresholds – Two separate response value ranges (1 kΩ to 10 MΩ) support pre-alarm and main alarm levels.
· Event logging with real-time clock – Stores historical alarm information with date and time stamps for fault tracing.
· Communication interface – Electrically isolated RS-485 interface supporting the Bender BMS protocol for networking with other monitoring devices.
· Analog output – Provides 0(4) to 20 mA analog output (electrically isolated), proportional to the measured insulation resistance, for connection to PLC or DCS systems.
· Comprehensive self-diagnosis – Automatic self-test and alarm functions continuously monitor the device’s own operating status.
· Two alarm relays – Two independent alarm relays with two changeover contacts each (250V/5A), selectable as normally open or normally closed, capable of activating external protection equipment.
· High-voltage system extension – When used with AGH675S-7 or AGH675S-7MV15 coupling devices, the monitoring range can be extended to medium-voltage systems up to 15.5 kV (e.g., medium-voltage variable frequency drives).
· Intuitive user interface – Backlit LCD display (2 lines of text), plus INFO, TEST, RESET and MENU keys for local parameter viewing and setting.
· Wide voltage range – Directly monitors AC and AC/DC systems up to 0‑793 V, or DC systems up to 0‑650 V.
3. Technical Specifications
· Rated monitoring voltage: AC, AC/DC 0‑793 V / DC 0‑650 V (IT system)
· Frequency range: AC 0‑460 Hz
· Response value range: 1 kΩ to 10 MΩ (two independently adjustable)
· Measurement principle: AMPPlus patented technology
· Alarm output: Two changeover relays (250V/5A), NO/NC selectable
· Analog output: 0(4) to 20 mA, electrically isolated
· Communication interface: RS-485 (BMS protocol), electrically isolated
· Operating power supply: DC 24 V
· Mounting: DIN rail
· Dimensions (W × H × D): 110 × 115 × 73 mm
· Operating temperature: -10°C to +55°C
· Protection rating: IP20
4. Typical Applications
· Power generation and distribution systems
· Industrial automation and production lines (inverters, variable frequency drives, thyristor-controlled circuits)
· Medical electrical facilities (operating rooms, intensive care units – isolated power systems)
· Medium-voltage variable frequency drive systems (with AGH675S coupler, up to 15.5 kV)
· Renewable energy (PV plants, wind farms – DC side insulation monitoring)
· Transportation (electric vehicles, ships, mobile generator sets)
· Oil and gas (explosion hazardous areas)
· Data centers and building power distribution (UPS systems, main and backup circuits)
Translation missing: en.general.search.loading