Bender IRDH275-435 B91065100 Insulation Monitoring Device

Product Overview

The Bender IRDH275-435 (Part No. B91065100) is an ISOMETER® Insulation Monitoring Device (IMD) designed for continuous monitoring of insulation resistance in ungrounded IT AC and DC electrical systems. It detects insulation faults at an early stage without disconnecting the power supply, improving electrical safety and system reliability.

The device is mainly used in industrial power systems, automation equipment, control cabinets, and critical electrical installations where uninterrupted operation is required.

Main Specifications

• Manufacturer: Bender
• Model: IRDH275-435
• Part Number: B91065100
• Series: ISOMETER® IRDH275
• Product Type:
  • Insulation Monitoring Device (IMD)
  • Ground Fault Monitoring Relay
  • Insulation Resistance Monitor
• System Type: IT (ungrounded) electrical systems
• Rated System Voltage:
  • AC 0…793 V
  • DC 0…650 V
• Supply Voltage:
  • AC 88…264 V
  • DC 77…286 V
• Power Consumption: ≤14 VA
• Mounting: DIN rail mounting

Technical Specifications

Functions

The IRDH275-435 provides:

• Continuous insulation resistance monitoring
• Detection of ground insulation faults
• Alarm output for insulation degradation
• Adjustable alarm thresholds
• Fault memory function
• Self-test function
• Real-time insulation status display

Working principle:

IT Power System → IRDH275-435 Measurement Circuit → Insulation Resistance Evaluation → Alarm Output / Control System

Features & Advantages

• Original Bender ISOMETER® industrial monitoring device
• Monitors insulation without interrupting power supply
• Suitable for AC, 3(N)AC, and DC systems
• Improves electrical system safety and availability
• Early warning before insulation failure
• Reliable operation in harsh industrial environments
• DIN rail installation saves cabinet space
• Suitable for retrofit and replacement applications

Applications

Used in:

• Industrial automation systems
• Power distribution cabinets
• CNC machines
• Medical electrical systems
• Marine electrical systems
• Renewable energy systems
• UPS and battery power systems
• Converter and drive systems

Typical applications:

• Ground fault monitoring
• Insulation degradation detection
• Preventive electrical maintenance
• Critical power system protection