Bender IR423-D4W-2 Insulation Monitoring Relay

Bender IR423-D4W-2 Insulation Monitoring Relay (ISOMETER®)

 

 

The Bender IR423-D4W-2 is an insulation monitoring relay (ISOMETER®) designed to continuously monitor the insulation resistance of unearthed (IT) AC systems, especially in mobile generators and industrial power systems.

It detects insulation faults before an earth fault becomes dangerous, improving system safety and preventing electrical damage.

Key Specifications

• Model: IR423-D4W-2
• Brand: Bender
• Series: ISOMETER® IR423
• Product Type: Insulation Monitoring Device / Relay
• System Voltage:
  • AC 0…300 V
• Supply Voltage:
  • AC/DC 70…300 V (variant dependent)
• Function:
  • Continuous insulation resistance monitoring
  • Earth fault detection in IT systems
• Display:
  • Multi-function LCD display
• Outputs:
  • 2 alarm relays (Alarm 1 / Alarm 2)
• Standards:
  • IEC 61557-8 compliant

What it does (simple explanation)

This device monitors whether electricity is “leaking” to ground:

Normal condition:

• High insulation resistance → system is safe

Fault condition:

• Insulation drops → warning/alarm/trip signal

System flow:

IT Power System (floating neutral)
↓
IR423 Monitoring Relay
↓
Alarm 1 / Alarm 2 relay output
↓
PLC / alarm / breaker system response

Key Functions

• Continuous insulation resistance measurement
• Early warning (pre-alarm + main alarm)
• Detection of earth leakage faults
• Monitoring of unearthed AC systems
• Self-diagnosis and connection monitoring
• Configurable response thresholds

Features & Advantages

• Designed for mobile generators and portable power systems
• High safety for IT electrical networks
• Two independent alarm levels
• LCD display for real-time insulation value
• Automatic self-monitoring function
• Suitable for harsh industrial environments (W version = ruggedized)
• Fast fault detection before shutdown or damage

Applications

• Mobile generator sets
• Construction site power systems
• Hospitals (IT medical power systems)
• Industrial isolation power networks
• Mining and offshore platforms
• Temporary power distribution systems