Description
The BENDER IRDH275-435 is an insulation monitoring device (IMD) specifically designed for unearthed (IT) AC and DC systems. It’s manufactured by Bender GmbH & Co. KG, a company known for electrical safety technologies.
Here’s a breakdown of its key features and functionalities:
Function 
The IRDH275-435 continuously monitors the insulation resistance of unearthed AC and DC electrical systems. Unearthed systems, also known as IT systems, intentionally lack a direct connection to ground. This design offers several advantages like improved safety for personnel and reduced risk of ground faults causing complete system shutdown. However, it also makes it challenging to detect developing insulation issues that could lead to arcing faults or equipment damage.
The IRDH275-435 addresses this challenge by injecting a small, safe AC test current into the system and measuring the resulting voltage drop. Based on this measurement, it calculates the insulation resistance and provides an indication of the system’s health.
Key Features:
- Suitable for Unearthed AC/DC Systems: Designed specifically for monitoring IT systems with rated voltage ranges:
- AC: 0…793 VAC
- DC: 0…650 VDC
- Early Fault Detection: Identifies developing insulation weaknesses before they escalate into arcing faults or equipment failures.
- Alarm Outputs: Provides various alarm outputs to notify operators of potential insulation issues, allowing for preventative maintenance.
- Communication Interface: May offer communication interfaces (e.g., RS485) for integration with building management systems or SCADA systems for centralized monitoring.
- Optional Features: Depending on the specific model variation (e.g., IRDH275-435 vs. IRDH275B-435), there might be optional features like different current outputs or external power supply compatibility for offline/standby systems.
Applications:
The BENDER IRDH275-435 is used in various applications where reliable insulation monitoring of unearthed AC and DC systems is critical, such as:
- Data Centers: Ensuring the uninterrupted operation of critical IT infrastructure by detecting potential insulation problems in power distribution systems.
- Wind Turbines: Monitoring the insulation health of wind turbine generators and associated electrical systems for improved safety and reliability.
- Hospitals and Healthcare Facilities: Maintaining a safe electrical environment for patients and medical equipment by ensuring proper insulation in power distribution systems.
- Industrial Automation Systems: Protecting sensitive electronics and preventing production downtime by detecting insulation issues before they cause electrical faults.
