BENDER IRDH275-427 ISOMETER Insulation Monitoring Device

Description

BENDER IRDH275-427 ISOMETER Insulation Monitoring Device

Product Dimensions：

The Bender IRDH275-427 is an A-ISOMETER® Insulation Monitoring Device. It continuously measures and monitors the insulation resistance of ungrounded AC, DC, and mixed AC/DC power supply systems (IT systems) without requiring system shutdown.

The suffix “-427” specifies its low-voltage auxiliary power supply rating.

Technical Parameters

Key Product Advantages

• AMPPlus Measuring Principle: Combines adaptive measuring signals to accurately monitor modern power systems containing rectifiers, variable frequency drives (VFDs), thyristors, and high system leakage capacitances.
• Two Independent Alarm Relays: Allows users to set up a two-tier warning system (e.g., Pre-warning on Alarm 1, Main trip/alarm on Alarm 2) to mitigate safety hazards before a full outage occurs.
• Automatic System Adaptation: Dynamically adapts to system leakage capacitance, reducing false tripping in complex installations.
• Continuous Self-Monitoring: Automatically tests internal hardware, wire connections, and ground references, illuminating a system fault LED and activating a fault relay if a connection or internal failure is detected.

Important Considerations & Precautions

• Low Supply Voltage Constraint: The -427 model specifically requires a low-voltage auxiliary supply (19.2–55V AC / 19.2–72V DC). Connecting it to a standard 110/230V line will severely damage the unit.
• Grounding Connection: Ensure the earth connection (E) and functional earth (KE) terminals are wired independently to reliable ground points to maintain measurement accuracy and self-monitoring capabilities.
• System Voltage Expansion: If monitoring circuits above 793V AC or 650V DC, an appropriate external coupling unit (such as the Bender AGH150W-4) must be paired with the device.
• High-Voltage Insulation Testing: Disconnect or isolate the IRDH275 measuring lines prior to performing high-voltage megohmmeter/dielectric tests on the main distribution power grid to protect the internal circuitry.

Product Applications

• Solar Photovoltaic (PV) Systems: Monitoring ungrounded DC and inverter circuits in commercial and utility-scale PV installations.
• Industrial IT Distribution Systems: Protecting ungrounded manufacturing networks with variable speed drives (VSDs), rectifiers, and heavy motor loads.
• UPS & Battery Systems: Safeguarding continuous power supply banks and battery energy storage systems (BESS) against ground faults.
• Marine & Offshore Operations: Ensuring high operational availability for electrical networks on ships, vessels, and offshore oil platforms where a first ground fault must not trigger a system trip.

Shipping Port: Xiamen, China

Payment: Bank of Chicago, Bank of Singapore

Express cooperation: fedex, DHL, UPS and your express account

Service: Professional Sales provides 24 hours /7 days online service

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