Bender – IR425‑D4‑1 – Insulation Monitor for AC/DC IT‑Systems, 15–460 Hz

The Bender IR425‑D4‑1 is a precision insulation monitoring device (ISOMETER®) for ungrounded AC/DC control circuits operating between 0–300 V. With selectable dual threshold alarms, adjustable response delay, and a multifunction LC display, this two-module unit fits DIN rail applications and ensures early ground fault detection in industrial and safety-critical environments.

 Key Specifications

• Model / P/N: IR425‑D4‑1 (B71036403 / B91036403)  

• System Voltage: 0–300 V (AC/DC), 15–460 Hz  

• Supply Voltage:

  • DC: 9.6–94 V

  • AC: 16–72 V, 15–460 Hz  

• Trip Response: 1–200 kΩ adjustable, with dual prewarning and alarm thresholds  

• Enclosure: 2‑module (36 mm), DIN-rail mount, IP20  

• Connections: Push-wire terminals (two per terminal) – B7 version; screw-type B9 also common  

• Display & Indicators: LC screen, Power/Alarm LEDs, internal/external test/reset buttons  

• Relay Outputs: 2 change-over (SPDT) alarm relays, configurable NO/NC & latching options  

• Certifications: IEC 61557‑8 (insulation monitoring), DIN EN 60204‑1, VDE 0100‑725  

• Dimensions: ~36 × 90 × 60 mm; weight ~0.62 lb (~0.28 kg)