The insulation monitoring relays of ABB 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. 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 include Continuous operation; Down-time reduction by providing early pre-warnings. Gaining time for maintenance planning; Monitoring of voltage free networks for early fault detection; Variants with rail & ship approvals; Safety and Protection; Safe and reliable detection of insulation faults according latest standards; Attractive portfolio for standard as well as more challenging applications; Can prevent fire due to fast and reliable earth fault detection; Built-in self-diagnosis and interrupted wire detection; Easy to Install; Clear visualization of device status via LEDs; Easy to adjust with rotary wheels & Variants with push-in terminals. Main features include Monitoring of system voltages up to 1500 V DC and 1100 V AC; Monitoring of system leakage capacitances up to 3000 µF; All kind of systems can be monitored: 2-wire, 3-wire, 4-wire as well as battery systems; Interrupted wire detection configurable & Non-volatile fault storage configurable.