Key Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | IRDH575B1W-435 |
| Manufacturer | BENDER |
| Product Type | Insulation Monitoring Device (IMD) |
| Rated Voltage | AC/DC 0-575V |
| Response Threshold Range | 1kΩ to 10MΩ (Adjustable) |
| Communication Interface | RS485 |
| Output Relays | 2 Independent Alarm Relays |
| Fault Location Function | Integrated test current generator for EDS |
| Display | Backlit LCD |
| System Type | IT, TT, TN-S, and Grounded Systems |
| Installation Type | Panel Mount (133x144x96mm) |
Product Introduction
Finding a ground fault in an ungrounded (IT) system without shutting down the process is a nightmare that keeps plant managers awake at night. The BENDER IRDH575B1W-435 solves this exact problem by acting as both a continuous insulation monitor and an active fault locator. I’ve installed these in hospital IT power systems and marine engine rooms where a single ground fault cannot be allowed to trip the main breaker.This specific B1W-435 variant handles a wide 0-575V AC/DC range, making it incredibly versatile for mixed-voltage industrial panels. Its standout feature is the built-in test current generator, which works with external current transformers to identify exactly which branch circuit is leaking. The backlit LCD gives you real-time leakage capacitance readings right on the panel face. Just be aware that the internal electronics are highly sensitive to moisture; I’ve seen these fail prematurely in damp, unheated outdoor enclosures. Keep them in a climate-controlled cabinet.
Quality SOP & Tech Pitfalls
We don’t just pull these from a shelf and ship them. Every IRDH575B1W-435 gets a visual inspection for terminal corrosion and PCB damage. We power it up on our test bench, verify the LCD backlight, and simulate an insulation drop to ensure the alarm relays click and the RS485 port reports the fault. We check the test current output and seal it in anti-static packaging with a logged test report.Here is where guys mess this up: forgetting to configure the system type. The IRDH575B1W-435 can monitor IT, TT, and TN-S systems, but it doesn’t auto-detect them. If you install this on a grounded TN-S system but leave the DIP switches set for an IT system, it will either fail to detect real faults or nuisance trip constantly. Always double-check the DIP switch matrix against your system grounding diagram before applying power.
Installation & Configuration Guide
- Pre-Installation: ⚠️ LOTO the panel. Verify zero energy. Photograph the existing wiring and all DIP switch positions. Ensure the panel environment is dry and within the operating temperature spec.
- Removal: Label the KE (earth), KI (insulation), and RS485 wires clearly. Release the DIN rail mounting clips. These units are heavy; support the module with your hand so it doesn’t drop and damage the backplane pins.
- Installation: Copy the DIP switch settings exactly. This is critical for matching the system grounding type and response thresholds. Slide the IRDH575B1W-435 onto the rail and press firmly to seat the rear connector.
- Power-On & Testing: Apply control power. Watch the LCD boot sequence. Verify the measured insulation resistance matches your expected baseline. Trigger a manual test using the built-in button to confirm the alarm relays and RS485 polling are functioning correctly.
Compatible Replacement Models
| Replacement Model | Compatibility Tier | Notes |
|---|---|---|
| BENDER IRDH575B1W-435 | ✅ Drop-in Replacement | Exact same hardware. Verify DIP switch settings match. |
| BENDER IRDH575B1-435 | ⚠️ Software Compatible | Same core specs, but lacks the “W” suffix (verify if “W” indicates a specific OEM firmware or wide-range variant). Budget 1 hour for verification. |
| BENDER IRDH575B2-435 | ⚠️ Software Compatible | Higher voltage variant (AC 340-760V). Will work on 575V systems, but requires parameter reconfiguration. |
| BENDER IRDH375B-435 | ❌ Hardware Mod Required | Lower-tier model without the advanced EDS fault location test current generator. Only use if fault location is no longer required. |
Frequently Asked Questions (FAQ)
Can this monitor a standard grounded TN-S system?
Yes, absolutely. The IRDH575B1W-435 is designed for both ungrounded (IT) and grounded (TN-S/TT) systems. Just make sure you set the DIP switches to the correct system type, or it won’t measure residual current properly.Will this work with my existing external current transformers?
Most likely, yes. The IRDH575 series uses standard BENDER test current frequencies. However, verify the part number on your existing EDS current transformers to ensure they are compatible with the IRDH575 test signal.I’m getting a nuisance alarm during motor startup. How do I fix it?
Motors cause massive inrush currents that look like ground faults. You need to increase the response threshold (kΩ setting) or adjust the time delay filter in the menu to ride through the startup transient.Does the RS485 port require a separate power supply?
No, the RS485 communication is powered directly from the module’s main control supply. Just ensure you use a properly terminated, shielded twisted-pair cable to prevent noise from tripping false alarms.Is this unit sensitive to ESD during installation?
Extremely. The internal signal processing board is highly sensitive. Always wear a grounded wrist strap when handling the module, and never touch the rear connector pins directly.Do you include the mounting hardware and manual?
Yes, the factory-sealed box includes the panel mounting brackets, terminal covers, and the quick-start wiring guide. If you need the full EDS configuration manual, we can provide a digital copy.
