Bender IRDH375 Advanced Ground Fault Monitor

Description

Key Technical Specifications

Product Introduction & Supply Chain Strategy

The Bender IRDH375 ISOMETER is an advanced insulation monitoring relay designed for ungrounded (IT) power distribution systems in critical industrial facilities, solar power stations, marine systems, and mining installations. Powered by Bender’s AMP-Plus measurement technology, it accurately evaluates ground insulation resistance across modern electrical networks containing variable frequency drives (VFDs), rectifiers, and high-capacity DC buses without triggering false alarms due to system leakage capacitance.

This product is a Brand New Surplus unit. It is not used, not pulled from a decommissioned plant, and not refurbished. All modules undergo rigorous quality verification to ensure OEM-level reliability.

Refurbished insulation monitors pose severe operational risks due to drifted reference resistors, degraded internal measurement transformers, and dried-out power supply capacitors. An undetected ground fault in an ungrounded system can cause catastrophic second-fault short circuits, arc flashes, and emergency plant shutdowns. Sourcing genuine New Surplus inventory guarantees original OEM measurement accuracy, lowers your Total Cost of Ownership (TCO), and provides immediate drop-in replacement without requiring panel modifications or electrical re-certification.

Installation

IRDH375

& Configuration Guide

Stage 1: Pre-Installation (Prep & Safety)

1. Execute Lock-Out/Tag-Out (LOTO) protocols on both the main network supply (Un) and auxiliary supply (Us).
2. Wear an anti-static wrist strap connected to a verified enclosure ground stud.
3. Document existing parameter configurations (R_{an1}, R_{an2} alarm response values, relay operation modes, and BMS network addresses) from the legacy unit.

Stage 2: Removal

1. Unplug or disconnect the wire terminal blocks from the top and bottom of the IRDH375 housing.
2. Release the DIN-rail locking latch using a flat-head screwdriver.
3. Lift the unit off the mounting rail and place it into ESD-safe packaging.

Stage 3: Installation (Clone & Seat)

1. Mount the replacement IRDH375 securely onto the DIN rail inside the control cabinet.
2. Reconnect the wiring connectors, ensuring that the system coupling terminals (L1/L2) and ground reference connections (E/KE) are firmly tightened.
3. Apply auxiliary supply power (Us) and navigate the front panel LCD menu to configure alarm thresholds, relay modes (fail-safe vs. non-fail-safe), and communication parameters to match original project settings.

Stage 4: Power-On & Testing

1. Apply main system voltage (Un) to the monitored power bus.
2. Verify the LCD display indicates real-time insulation resistance values in MΩ without alarm fault indications.
3. Press the front panel TEST button to initiate a internal self-test cycle; verify that both alarm LEDs illuminate and output relays trigger as configured.

Firmware/Software Versions & Upgrade Notes

• System Compatibility: Ensure the device’s BMS protocol software revision matches remote indicator panels (e.g., Bender MK2430 / TM series) or central SCADA gateways.
• Backward Compatibility: The IRDH375 is physically and functionally backward compatible with the IRDH275/IRDH265 series; however, confirm analog output range parameters (0–20 mA vs 4–20 mA) during setup.
• Firmware Risks: Never disconnect auxiliary power while saving parameters or running system resets. Interrupted EEPROM writes can corrupt system memory, causing startup fault loops.

Frequently Asked Questions (FAQ)

Q: Is this Bender IRDH375 unit genuine New Surplus or a refurbished module?

A: This module is 100% genuine New Surplus. It has zero field operating hours, pristine terminal connectors, unmarred mounting latches, and original factory calibration. It is not used, repaired, or refurbished.

Q: Why should I choose New Surplus over a cheaper refurbished ?

A: Refurbished insulation monitoring devices often suffer from drifted internal measurement tolerances and aged capacitors. In ungrounded IT networks, a compromised monitor may fail to detect insulation breakdown, leading to destructive double-phase ground faults. New Surplus guarantees original OEM safety performance and full service life.

Q: How do you verify the functionality of this unit before shipping?

A: Every unit undergoes multi-point Quality Control verification. Technicians inspect physical casing integrity, perform auxiliary power-up boot testing, verify LCD menu navigation, and conduct functional test/reset loop checks to confirm relay operation.

Q: Is the Bender still in active production by the OEM?

A: The is a legacy model from Bender. Acquiring New Surplus units enables plant maintenance teams to maintain strategic buffer stock, allowing direct hardware swaps without redesigning cabinet layouts or upgrading to new product generations.

Q: Does this unit require external coupling devices for standard voltage networks?

A: For AC networks up to 793 V and DC networks up to 650 V, the connects directly. For higher system voltages (e.g., 1000 V or higher), an external Bender coupling device (such as the AGH series) must be installed.

Q: What warranty coverage applies to this unit?

A: This New Surplus Bender includes a comprehensive 1-Year functional replacement warranty covering electronic and manufacturing defects.