Description
Bender IRDH575B1W-435 | 20–575 V AC/DC Monitoring
Product Introduction
In an unearthed power system, the first insulation fault may not immediately interrupt operation—but it can create the conditions for a more serious second fault. The Bender IRDH575B1W-435 ISOMETER is designed to monitor insulation resistance and support insulation-fault detection in compatible IT electrical systems.
This specific B1W-435 variant combines the IRDH575B monitoring platform with the W option for increased mechanical and environmental resistance. The B1 version monitors AC and DC systems in the 20–575 V range, while its auxiliary supply accepts 88–264 VAC or 77–286 VDC. The IRDH575 platform also supports selective insulation fault location through compatible EDS equipment. For replacement procurement, verify the complete model, article number, host-system voltage, and existing EDS/BMS configuration before ordering.
IRDH575B1W-435
Key Technical Specifications
- Manufacturer: Bender
- Model: IRDH575B1W-435
- OEM Article Number: B91065500W
- Product Series: ISOMETER IRDH575
- Device Type: Insulation monitoring device
- Monitored System Type: Unearthed AC, 3(N)AC, and DC systems
- Nominal AC System Voltage: 20–575 VAC, B1 variant
- Nominal DC System Voltage: 20–575 VDC, B1 variant
- Auxiliary Supply (AC): 88–264 VAC
- Auxiliary Supply (DC): 77–286 VDC
- Auxiliary Supply Frequency: 42–460 Hz
- Response Value Range: 1 kΩ–10 MΩ
- Communication Interface: RS-485 using BMS protocol
- Insulation Fault Location: Integrated test generator/controller for compatible EDS systems
- Alarm Outputs: Three changeover contacts, as documented for the IRDH575 platform
- Option W: Increased shock and vibration resistance; special electronics coating for improved resistance to mechanical stress and moisture
- Mounting: Panel mounting; confirm cutout and accessory requirements
- Protection Rating: Verify the required enclosure/sealing arrangement and installed accessories
Specifications are based on Bender IRDH575 ordering and technical documentation. Confirm the physical nameplate and applicable manual revision before using these values as commissioning criteria.
Global Sourcing & Live-Test SOP
For a surplus IRDH575B1W-435, verify the complete model and the W-option hardware before describing the unit as suitable for a demanding environment.
Inbound Verification
- Confirm the full IRDH575B1W-435 marking.
- Verify article number B91065500W, where present.
- Photograph the nameplate, front panel, terminals, and enclosure.
- Record serial number and hardware revision, if available.
- Inspect the housing, display, keys, and terminal areas for damage or corrosion.
- Check for signs of moisture ingress or unauthorized repair.
Authenticity and Configuration Review
- Compare the model and article number against Bender documentation.
- Verify the auxiliary supply range before applying power.
- Confirm the monitored system voltage and AC/DC application.
- Identify the installed BMS wiring and EDS system configuration, if applicable.
- Verify that the W option is explicitly marked on the unit rather than inferred from appearance.
Functional Validation
- Energize only with a verified compatible auxiliary supply.
- Check startup, display operation, and available self-test functions.
- Test insulation-monitoring response using an appropriate controlled setup.
- Verify alarm relay operation and configured response thresholds.
- Test analog output and BMS communication where suitable equipment is available.
- If EDS fault-location functionality is part of the application, verify it with compatible equipment.
- Record the test setup, configuration, and observed results.
- Do not claim calibration or functional testing unless it has actually been performed and documented.
Extended Test and Shipment
- If extended testing is performed, record its duration and operating conditions.
- Document the test date, supply voltage, alarm behavior, and communication status.
- Protect the device from impact, moisture, and contamination during shipment.
- Use suitable protective packaging and include only accessories explicitly identified in the sale.
Field Engineer’s Pitfall Guide
- ❗ Do not confuse the B1-435 with B2 or other voltage variants. The B1-435 is rated for 20–575 V AC/DC monitoring. Other IRDH575 variants have different system-voltage ranges. Verify the complete model and monitored circuit before commissioning.
- ❗ The W option is not a universal environmental rating. It provides increased shock and vibration resistance and improved moisture resistance through special electronics coating. It does not mean the complete device is waterproof or suitable for any installation environment.
- ❗ Check the existing EDS and BMS architecture. The IRDH575 supports selective insulation fault location with compatible EDS equipment and communicates using BMS. Confirm the installed devices, wiring, and settings before assuming the replacement will integrate without configuration work.
Intent-Driven FAQ
What is the Bender IRDH575B1W-435 used for?
It monitors insulation resistance in unearthed AC/DC systems and supports insulation fault location with compatible EDS equipment.
What is the OEM article number?
The documented article number is B91065500W.
What system voltage can the monitor?
The B1 version is documented for 20–575 VAC and 20–575 VDC systems. Verify the nameplate and application requirements before installation.
What auxiliary supply does it require?
The documented auxiliary supply is 88–264 VAC or 77–286 VDC.
What does the W suffix mean?
The W option indicates increased resistance to shock and vibration, along with improved moisture resistance through a special electronics coating.
Does the support BMS communication?
The IRDH575B platform includes an RS-485 BMS interface. Confirm the device configuration and existing network settings during replacement.
What should I verify before purchasing a surplus unit?
Confirm the full model and article number, monitored-system voltage, auxiliary supply, W-option marking, terminal condition, and documented test status. Verify warranty and included accessories with the seller.
Procurement Note
This listing describes the documented Bender , article B91065500W. It does not imply that a specific surplus unit has been tested, calibrated, or supplied with a warranty. Confirm the physical nameplate, condition, included accessories, and test status before publishing.
