ABB CM-IWS.2S Insulation Monitoring Relay, 24-240 V AC/DC, 0-500 V, 1 kΩ-10 MΩ, 2 SPDT 1SVR730670R0200

Monitor insulation integrity in AC, DC, and mixed AC/DC IT systems with the ABB CM-IWS.2S, covering a measuring voltage range up to 500 V and insulation resistance from 1 kΩ to 10 MΩ. Two independently adjustable thresholds provide early warning and alarm for insulation faults, with response times under 500 ms.

Overview

The CM-IWS.2S is a monitoring relay designed for continuous insulation supervision in ungrounded (IT) systems. It operates on a wide auxiliary supply of 24-240 V AC/DC and supports monitored system frequencies from 15 to 400 Hz. The relay features two SPDT output contacts rated up to 250 V AC / 4 A, and clear LED indication for operating status and each insulation fault threshold.

What stands out

• Monitors AC, DC, and combined AC/DC IT systems
• Wide auxiliary supply range: 24-240 V AC/DC
• Two independent insulation resistance thresholds
• Fast response: less than 500 ms
• DIN rail mounting for easy installation

Technical details

• Measuring voltage range: 0-500 V AC/DC
• Insulation resistance range: 1 kΩ - 10 MΩ
• Output contacts: 2 x 1 c/o (SPDT)
• Contact rating: 250 V AC, 4 A (AC-12); 24 V DC, 2 A (DC-12)
• Operating temperature: -25 to +60 °C
• Degree of protection: IP50 (housing), IP20 (terminals)
• Terminal type: Screw terminals
• Rated impulse withstand voltage: 6 kV
• Overvoltage category: III

Our verdict

A reliable insulation monitoring solution for industrial and commercial IT systems, offering flexible voltage ranges and dual threshold detection in a compact DIN-rail module.