The ABB CM-ESS.S (SVRR) is a single-phase voltage monitoring relay designed for reliable overvoltage and undervoltage protection in industrial and commercial electrical systems. Operating with a rated control supply voltage of – V AC, this relay features two changeover (SPDT) contacts rated at V / A for flexible integration into control circuits.

The device supports four selectable measuring ranges (– V, – V, – V, – V) using a true RMS measuring principle, ensuring precise monitoring of both AC and DC voltages. The relay is configurable for either overvoltage or undervoltage detection, with an adjustable hysteresis (–% of the threshold value) and a tripping delay that can be set from instantaneous up to seconds. It is equipped with screw terminals and fits standard DIN rail mounting, making installation straightforward in control panels.

Key Features:

• Control supply voltage: – V AC

• Measuring ranges: – V, – V, – V, – V (AC/DC, true RMS)

• Output: x SPDT (changeover) contacts, V / A

• Configurable for overvoltage or undervoltage monitoring

• Adjustable hysteresis: –% of threshold

• Adjustable tripping delay: s (instantaneous) or .– s

• Screw terminal connections

• DIN rail mounting (. mm wide)

• Degree of protection: Housing IP, terminals IP

• Electrical durability: , cycles (AC-)

• Mechanical durability: ,, cycles

• Standards: IEC/EN -, UL , CAN/CSA C. No.

ABB – CM-ESS.2S (1SVR730831R0400) – Single-Phase Voltage Monitoring Relay