The CM-IW series insulation monitoring relays provide continuous insulation monitoring for unearthed IT AC, DC, and mixed AC/DC systems up to 1500 V, including photovoltaic and battery-powered applications. The device features configurable prewarning (20 kΩ to 2 MΩ) and warning (1 kΩ to 250 kΩ) thresholds, a 90 mm width, and dual relay outputs for alarm and prewarning states with selectable open- or closed-circuit operation. It supports earth leakage capacitances up to 3000 μF, includes broken-wire detection on all measuring terminals, and performs automatic and manual self-tests. The insulation resistance is displayed via an LED chain and complies with IEC/EN 61557-8. Adjustment is made through front-mounted rotary switches, and an external test/reset pushbutton can be connected. The unit operates without a coupling device and monitors systems even with voltage-free mains.
Insulation Monitoring Relays
Reliable insulation monitoring of your IT system
The insulation monitoring relays of the CM-IWx range guarantee a continuous insulation monitoring of an IT system. The devices recognize insulation faults as they develop and trip immediately if the value has fallen below the minimum set threshold (1-200 kOhm). This ensures a reliable operation of the system and prevents operational interruption caused by a second, more severe, insulation fault which may lead to a short circuit tripping the main circuit breaker.
Main Benefits
Main Features
| ABB Inc. | |
|---|---|
| Product Category | Protective Relays and Monitoring Relays |
| Product Number | CM-IW Series |
| Product Name | Insulation Monitoring Relays |
| Features | Latching (optional feature) |
