The BENDER IRDH575B1W-435 is a high-performance Insulation Monitoring Device (IMD) designed for continuous, real-time monitoring of insulation resistance in isolated (IT) power systems operating at voltages up to 1000 V AC/DC. As part of BENDER’s globally trusted portfolio of electrical safety solutions—widely adopted in healthcare, data centers, marine, rail, and industrial automation—the IRDH575B1W-435 detects early-stage insulation degradation before it leads to dangerous ground faults, equipment damage, or unplanned downtime.
Unlike conventional earth leakage protection that only reacts after a fault occurs, the IRDH575B1W-435 proactively measures insulation resistance between live conductors and earth, providing warnings at user-defined thresholds (e.g., 50 kΩ pre-alarm, 20 kΩ main alarm). This enables predictive maintenance and ensures compliance with stringent safety standards such as IEC 60364-7-710 (medical locations), NEC Article 517, and IEC 61557-8. The device features automatic test functionality, two potential-free relay outputs (for alarm and control), and optional RS485 Modbus RTU communication (via integrated interface), allowing seamless integration into building management systems (BMS) or SCADA platforms.
Housed in a compact 70 mm wide DIN-rail enclosure, the IRDH575B1W-435 supports both AC and DC IT systems, including those with variable frequency drives (VFDs) and rectifier loads, thanks to its advanced measurement technology that filters out system noise and harmonics. Its robust design, self-diagnostics, and compliance with international approvals (UL, CE, cULus) make it a cornerstone of electrical safety in mission-critical infrastructure where power continuity and personnel protection are non-negotiable.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Model | IRDH575B1W-435 |
| Manufacturer | BENDER GmbH & Co. KG |
| Type | Insulation Monitoring Device (IMD) |
| System Type | IT (isolated) networks – AC, DC, or AC/DC mixed |
| Nominal Voltage Range | 0 – 1000 V AC/DC |
| Measuring Range | 1 kΩ – 10 MΩ (adjustable response thresholds) |
| Accuracy | ±5% of reading (typical) |
| Test Method | Automatic DC injection with adaptive filtering |
| Relay Outputs | 2 x potential-free changeover contacts (alarm + warning) |
| Communication | Optional RS485 (Modbus RTU) – built-in |
| Power Supply | 85–265 V AC/DC (universal) |
| Operating Temperature | -25°C to +55°C |
| Mounting | DIN rail (EN 60715) |
| Approvals | CE, UL 61010-1, cULus, IEC 61557-8, IEC 61010 |
Main Features and Advantages
Proactive Fault Prevention: The IRDH575B1W-435 doesn’t wait for a short circuit—it identifies deteriorating insulation before a first ground fault occurs, enabling scheduled maintenance instead of emergency shutdowns. This is critical in hospitals (operating rooms), data centers (server racks), and ships (navigation systems), where even a momentary power loss is unacceptable.
Universal Compatibility: Works reliably in complex modern systems containing non-linear loads like UPS units, inverters, and VFDs. BENDER’s patented measurement technology rejects interference from switching frequencies and DC components, ensuring stable readings even in noisy environments.
Integrated Diagnostics & Communication: Built-in self-test verifies internal circuitry integrity. The optional Modbus RTU interface allows remote monitoring of insulation resistance values, device status, and alarm history—ideal for smart buildings and Industry 4.0 architectures.
Compact & Reliable: Despite its advanced capabilities, the IRDH575B1W-435 fits in just 70 mm of panel space. No moving parts, convection cooling, and solid-state design ensure long service life with zero maintenance.
Safety Compliance: Fully compliant with medical IT system standards (IEC 60364-7-710), making it suitable for Group 2 medical locations where patient-connected equipment demands the highest level of electrical safety.
Application Field
- Healthcare: Monitoring isolated power systems in operating theaters, ICUs, and neonatal units per NFPA 99 and IEC 60364-7-710.
- Data Centers: Protecting critical IT loads on isolated UPS-backed IT networks to prevent cascading failures.
- Marine & Offshore: Ensuring electrical safety on ships and platforms where single ground faults can disable navigation or propulsion.
- Rail & Transportation: Used in traction power substations and signaling systems requiring uninterrupted operation.
- Industrial Automation: Safeguarding production lines with IT-supplied robotic cells or explosion-hazardous zones (ATEX support via system design).
- Renewable Energy: Monitoring DC insulation in solar farms and battery storage systems.
Related Products
- ES710 Series: BENDER’s medical isolation transformers often paired with the IRDH575B1W-435 in hospital IT systems.
- RCM Series: Residual Current Monitors for TT/TN systems—complementary to IMDs in hybrid installations.
- ISOMETER® iso685: Higher-end IMD with Ethernet, touchscreen, and multi-circuit monitoring.
- MK2430: BMS gateway for integrating multiple BENDER devices into BACnet or KNX systems.
- IRDH265: Cost-effective alternative for basic applications without communication.
- ANM420: Alarm display unit for local visualization of IMD status in plant rooms.
Installation and Maintenance
Installation Tips:
- Install only in IT (ungrounded) systems—never in TN or TT networks.
- Connect the E (earth) terminal securely to the installation’s protective earth.
- Keep measuring leads short and twisted to reduce EMI pickup.
- For systems with large capacitance (>1 µF), use the optional coupling device (e.g., AGH520) to stabilize measurements.
Maintenance:
- The IRDH575B1W-435 requires no routine calibration—factory-calibrated for life.
- Perform a manual test monthly using the front-panel button to verify alarm functionality.
- Monitor insulation trends via Modbus to detect gradual degradation (e.g., due to moisture ingress).
- Replace only if self-diagnostics indicate internal fault or after exposure to severe overvoltage.
