Description
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product model | IRDH575B1W-435 |
| Manufacturer | Bender |
| Product family | ISOMETER IRDH575 |
| Product type | Insulation monitoring device |
| Monitored system | Unearthed AC, 3-phase AC, AC/DC, and DC IT systems |
| Nominal system voltage | 20–575 V AC / DC |
| AC frequency range | 50–460 Hz |
| Auxiliary supply | 88–264 V AC or 77–286 V DC |
| Auxiliary supply frequency | 42–460 Hz |
| Power consumption | ≤14 VA |
| Insulation resistance response range | 1 kΩ–10 MΩ |
| Measuring voltage | ≤40 V |
| Maximum system leakage capacitance | 500 μF |
| Fault-location current | Selectable: 1, 2.5, 10, 25, or 50 mA |
| Display | Backlit 4 × 16-character LCD |
| Alarm relays | 3 changeover contacts |
| Communication | RS-485 / BMS protocol |
| Maximum RS-485 cable length | 1,200 m |
| Analog output | 0/4–20 mA, maximum load 500 Ω |
| Standard protection rating | IP30 internal; IP20 terminals |
| Door-mount protection | IP40; IP42 with panel seal |
| Protection with transparent cover | IP65 |
| Mounting | Panel mounting |
| Panel cutout | 138 × 90 mm |
| Dimensions | 144 × 96 mm front panel |
| Weight | ≤900 g |
| W-option operating temperature | -25 to +70 °C |
| W-option shock resistance | 30 g / 11 ms |
| W-option vibration resistance | 1.6 mm at 10–25 Hz; 4 g at 25–150 Hz |
| Associated article number | B91065500W |
The W option provides increased mechanical resistance compared with the standard version. The listed article number for the W variant is B91065500W. Confirm the full nameplate before treating the standard B1-435 ratings as sufficient for a replacement.
IRDH575B1W-435
Product Introduction
The Bender IRDH575B1W-435 is an insulation monitoring device for unearthed power systems used in industrial, marine, and other electrical installations. It continuously measures insulation resistance between live conductors and earth, providing separate warning and alarm thresholds. Its integrated fault-location function can work with compatible EDS4-series evaluators and measuring current transformers to identify the affected outgoing circuit.
The W variant is intended for installations exposed to increased mechanical stress, including shipboard and vibration-prone environments. The unit also provides RS-485 communication using Bender’s BMS protocol, an analog measurement output, and stored alarm history.
Application Scenarios & Field Pitfalls
In an unearthed IT power system, the first insulation fault may not immediately interrupt power, but it can indicate deteriorating insulation and increase the risk of a second fault. The IRDH575B1W-435 provides continuous monitoring and can initiate selective fault-location procedures when connected to compatible EDS equipment.
Typical application areas
- Marine electrical systems: Insulation monitoring in shipboard distribution networks exposed to vibration and mechanical shock.
- Industrial process plants: Monitoring unearthed AC/DC distribution systems supplying drives, instrumentation, and control equipment.
- Power generation: Detection of insulation deterioration in auxiliary power distribution networks.
- Rail and mobile equipment: Insulation supervision in electrical systems subject to mechanical vibration.
Field pitfalls
1. Distinguish the monitored voltage from the auxiliary supply. The B1-435 measures systems up to 575 V AC/DC, while its own supply is 88–264 V AC or 77–286 V DC. These are separate circuits. Confirm both ratings against the nameplate and wiring diagram before energizing.
2. Check the W mechanical-resistance requirement. The W option is intended for higher shock and vibration exposure. Do not assume a standard IRDH575B1-435 has the same mechanical qualification or operating-temperature range.
3. Verify EDS compatibility and locating-current settings. Selective fault location requires compatible EDS4-series evaluators and measuring current transformers. In sensitive DC control circuits, Bender recommends limiting the locating current to 2.5 mA or, if necessary, 1 mA to reduce interference with PLC inputs.
Bender
4. Check RS-485 termination and bus wiring. The BMS interface supports cable lengths up to 1,200 m under the specified cable arrangement. Use the correct twisted-pair cable, shield grounding, and 120 Ω termination where required. Incorrect termination or topology can cause intermittent communication.
5. Do not confuse enclosure protection with panel protection. The basic device has different protection ratings for its internal components and terminals. IP42 requires the specified panel seal; IP65 requires the transparent front cover. Confirm the installed accessories and cabinet environment.
Related Products
- IRDH575B1-435 — Standard mechanical version of the B1-435 insulation monitor; does not include the W option’s enhanced shock and vibration resistance.
- IRDH575B1-427 — Similar monitored-voltage range, but uses a 19.2–72 V DC auxiliary supply instead of the B1-435 supply arrangement.
- IRDH575B1-4235 — Lower monitored-voltage version for AC/DC systems up to 150 V, with the higher auxiliary-supply range.
- IRDH575B2-435 — Higher-voltage monitored-system variant, rated for 340–760 V AC and 340–575 V DC.
- EDS460 — Insulation fault locator for identifying faulty outgoing circuits in compatible IRDH575 systems.
- EDS461 — Insulation fault locator suited to control circuits, including sensitive PLC supply circuits.
- W…/8000 Measuring Current Transformers — Current transformers used with compatible EDS equipment for detecting insulation fault-location current.
These products form part of the Bender insulation monitoring and fault-location system. They are complementary components, not direct substitutes for the IRDH575.
Procurement note: Specify the complete IRDH575B1W-435 designation and article number B91065500W. Verify the auxiliary supply, W mechanical option, monitored-system voltage, terminal arrangement, and existing EDS configuration before approving a replacement.
