{"product_id":"bender-irdh375-425-793v-650v-insulation-monitor-for-ac-dc-it-systems","title":"Bender IRDH375B-425 793V 650V Insulation Monitor for AC DC IT Systems","description":"\u003cdiv\u003e\u003cspan\u003eThe IRDH375B-425 is an advanced insulation monitoring device from Bender, designed for unearthed AC, AC\/DC, and DC power systems (IT systems). Its core function is to continuously monitor the insulation resistance of the main circuit, promptly issuing fault warnings when insulation levels fall below configured thresholds.The device complies with the requirements of IEC 61557‑8 and DIN EN 61557‑8, as well as standards such as NEC 250.21(B) and CEC 10-106(2) for ground detectors in ungrounded systems, delivering reliable safety monitoring for demanding industrial applications.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eThe IRDH375B-425 operates on a wide-range power supply (AC 88…264 V \/ DC 77…286 V) and features a panel‑mounted design suitable for control cabinet door installation.The “B” suffix in the model number indicates that this device includes four advanced features compared to the standard IRDH375-425: a memory with real‑time clock for date‑ and time‑stamped alarm storage; an electrically isolated RS‑485 interface supporting the BMS protocol; an ISOMETER® disconnecting relay for coordinated use in coupled IT systems; and an isolated 0(4)…20 mA analog current output.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eKey Features \u0026amp; Functions\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Patented AMPPlus Measuring Principle – The IRDH375B-425 employs Bender‘s patented AMPPlus measuring technology, which ensures accurate insulation monitoring even in systems with extensive DC components and high leakage capacitances – including pure DC systems, systems with rectifiers, and those with variable‑frequency drives (VFDs).\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Two Independently Adjustable Response Values – The device features two separately configurable alarm thresholds (Alarm 1 and Alarm 2), adjustable from 1 kΩ to 10 MΩ, allowing users to distinguish between pre‑warning and critical alarm levels for flexible system safety configuration.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Automatic Adaptation to System Leakage Capacitance – The device automatically adapts to the existing system leakage capacitance (maximum permissible ≤ 500 μF), optimising measurement time and ensuring dependable operation without manual calibration, displaying the measured capacitance value for on‑site diagnosis.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Backlit Two‑Line LC Display – Equipped with a backlit two‑line LC display, the device presents measured insulation resistance values and system parameters. On‑device operation is facilitated by four front‑panel keys: INFO, TEST, RESET, and MENU. The display also supports external kΩ measuring instrument connection.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Memory with Real‑Time Clock – The device features built‑in alarm storage with a real‑time clock, recording all alarm messages along with precise date and time stamps. This aids in troubleshooting, maintenance scheduling, and event analysis.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Electrical‑Isolated RS‑485 Interface with BMS Protocol – An electrically isolated RS‑485 interface supporting the Bender Measuring Device Interface (BMS) protocol is standard, enabling seamless data exchange with other Bender devices, central monitoring systems, and PLCs.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Isolated 0(4)…20 mA Analog Current Output – A galvanically isolated analog current output (configurable to 0…20 mA or 4…20 mA) provides an output signal proportional to the measured insulation resistance, allowing integration with external measuring instruments, PLCs, or SCADA systems for remote monitoring.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· ISOMETER® Disconnecting Relay – An integrated disconnecting relay controlled via external terminals enables the ISOMETER® to be temporarily disconnected from the monitored IT system, an essential feature when operating multiple devices in coupled IT systems to ensure that only one remains active at any given time.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Automatic Device Self‑Test – An automatic self‑test function continuously verifies the internal measuring circuits, system control components, and earth connections. If the device detects an internal fault or connection break, a dedicated system fault relay and LED provide immediate indication of the issue.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· External Test, Reset, and External kΩ Display – External push‑buttons can be connected for device and connection testing, or for resetting stored fault messages. An external kΩ measuring instrument can be connected to remotely display the measured insulation resistance, enhancing operational flexibility and convenience.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Voltage Extension via Coupling Devices – The nominal system voltage range can be extended using appropriate Bender coupling devices (e.g., AGH series). With coupling devices, the monitoring range can be extended to DC 0…1760 V or 3(N)\/AC 0…7200 V, making the device suitable for medium‑ and high‑voltage IT systems.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· De‑Energised System Monitoring – As the device operates on an external power supply, it can monitor the system even when the main circuit is de‑energised, ensuring continuous safety oversight during maintenance or system shutdown periods.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· “W” Version for Harsh Environments (optional) – For applications requiring enhanced mechanical durability, devices with the “W” suffix provide improved shock and vibration resistance, with a special varnish coating applied to the electronics to offer higher resistance against mechanical stress and moisture, making them suitable for shipboard installations, railway rolling stock, and seismic environments.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eTechnical Specifications\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Nominal system voltage (Uₙ): 3(N)AC 0…793 V \/ AC\/DC 0…793 V; DC 0…650 V\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Nominal system frequency: DC, 0.2…460 Hz\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Supply voltage (Uₛ): AC 88…264 V (50…60 Hz); DC 77…286 V\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Response value range (Rₐₙ₁ \/ Rₐₙ₂): 1 kΩ … 10 MΩ, two thresholds independently adjustable\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Maximum permissible system leakage capacitance: ≤ 500 μF\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Measuring principle: AMPPlus (patented measuring pulse method)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Display: Backlit two‑line LC display\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Alarm outputs: Two independent changeover contacts (K1, K2) for Alarm 1 and Alarm 2, configurable for N\/O or N\/C operation\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· System fault relay: One changeover contact (K3), N\/C operation, for device‑internal fault reporting\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Communication interface: RS‑485, electrically isolated, supporting BMS protocol\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Analog output: 0(4)…20 mA, galvanically isolated\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Fault memory: Built‑in storage with real‑time clock for date‑ and time‑stamped alarm message recording\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Disconnection function: Internal ISOMETER® disconnecting relay for coupled IT system operation\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Response time: ≤ 5 s (at R_F = 0.5 × R_an and C_e = 1 μF)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Measurement accuracy: 1 kΩ…1 MΩ: ±15% ±1 kΩ; 1 kΩ…10 MΩ: ±15% ±0.1 MΩ\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Connection monitoring: Yes, test and reset via external push‑buttons\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Operating temperature: –10 °C … +55 °C\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Storage temperature: –40 °C … +70 °C\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Climatic class: According to IEC 60721‑3‑3 (class 3K5; 5…95% relative humidity, no condensation)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Protection class: Terminals IP30, enclosure IP20\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Mounting: Panel‑mounted (control cabinet door)\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Panel cutout: 138 × 68 mm\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Dimensions (W × H × D): 144 × 133 × 72 mm\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Weight: ≤ 510 g\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Order number: B91065005\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eTypical Applications\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Industrial IT systems – Insulation monitoring for AC, DC, and combined AC\/DC unearthed systems incorporating rectifiers, frequency converters, output chokes, thyristor‑controlled DC drives, switch‑mode power supplies, and other power electronic loads.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· UPS and battery systems – Continuous monitoring of insulation integrity in uninterruptible power supplies and battery backup installations.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· High‑leakage‑capacitance IT systems – Installations where interference suppression filters, EMI filters, or long cable runs generate significant leakage capacitance to earth, such as large plants and data centres.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Mixed‑voltage networks – Complex systems where AC and DC components operate within the same unearthed network, requiring reliable monitoring under fluctuating operational conditions.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Coupled IT systems – Installations where multiple IT subsystems are interconnected, requiring coordinated insulation monitoring with the integrated disconnecting relay to ensure only one ISOMETER® remains active at any given time.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Phase‑controlled heating systems – Monitoring insulation resistance in systems using phase‑angle control for heating elements.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Offline \/ de‑energised system monitoring – Applications where continuous insulation monitoring is required even when the main circuit is de‑energised, such as during maintenance periods.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Extended‑voltage applications – Through coupling devices, the monitoring range can be extended to DC 0…1760 V or 3(N)\/AC 0…7200 V, making the device suitable for medium‑voltage IT systems.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003e· Renewable energy systems – Photovoltaic and wind power IT systems requiring reliable insulation monitoring under variable operating conditions.\u003c\/span\u003e\u003c\/div\u003e","brand":"Bender","offers":[{"title":"Default Title","offer_id":44095249776728,"sku":null,"price":2440.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0580\/2799\/9320\/files\/IRDH375B-435..jpg?v=1778134003","url":"https:\/\/gexufein.com\/products\/bender-irdh375-425-793v-650v-insulation-monitor-for-ac-dc-it-systems","provider":"Gexufein Automation","version":"1.0","type":"link"}