ABB 1SVR730841R0400

The CM-SRS.21S current monitoring relay is part of the CM range, specifically engineered for single-phase monitoring. Operating within a control supply voltage range of 110 - 130 V AC, this relay is equipped with a 2 c/o (SPDT) output, suitable for a maximum contact rating of 250 V / 4 A.

This device employs an RMS measuring principle for both DC and AC currents, accommodating three distinct measuring ranges: 3-30 mA, 10-100 mA, and 0.1-1 A. Configurable options allow for monitoring of overcurrent or undercurrent conditions, with adjustable hysteresis settable between 3 to 30 % of the threshold value. The tripping delay can be tuned from instantaneous up to 30 seconds.

To prevent unauthorized adjustments, a sealable transparent cover is available as an accessory. The connection terminals utilize screw technology with double-chamber cage connections, ensuring secure connectivity.

In terms of dimensions, the relay measures 22.5 mm in width, 85.6 mm in height, and 103.7 mm in depth, with a net weight of 0.179 kg. The device complies with several standards including IEC/EN 60255-27 and UL 508, and is rated for environmental operation between -20 °C and +60 °C.