Description
ABB CM-MSS THERMISTOR MOTOR PROTECTION RELAY CM-MSS.31S 1SVR730712R1400 (NEW OPEN BOX)
ABB
CM-MSS
CM-MSS.31S
THERMISTOR MOTOR PROTECTION RELAY
1SVR730712R1400
TYPE A
24 – 240 V / 15-400 Hz
THE CM-MSS.31S BELONGS TO THE CM-MSS THERMISTOR MOTOR PROTECTION RELAY RANGE. IT OPERATES WITH A RATED CONTROL SUPPLY VOLTAGE OF 24 – 240 V AC / DC AND HAS A 1 N/C + 1 N/O (SPDT) OUTPUT WITH CONTACTS RATED AT 250 V / 4 A. IT FEATURES ONE SENSOR CIRCUIT TO MONITOR PTC TEMPERATURE SENSORS AND WORKS ACCORDING TO THE CLOSED-CIRCUIT PRINCIPLE. THE SENSOR CIRCUIT OF THE CM-MSS.31S IS SHORT-CIRCUIT, AS WELL AS INTERRUPTED-WIRE MONITORED AND THE RELAY CAN BE RESET AUTOMATICALLY, MANUALLY OR REMOTELY AFTER THE FAILURE HAS BEEN REMOVED. THIS PROTECTION RELAY IS CERTIFIED ACCORDING TO THE ATEX DIRECTIVE 94/9/EC AND IS EQUIPPED WITH A RESET / TEST BUTTON. A SEALABLE TRANSPARENT COVER FOR PROTECTION AGAINST UNAUTHORIZED CHANGES IS AVAILABLE AS ACCESSORY. THE DEVICE OFFERS SCREW CONNECTION TECHNOLOGY WITH DOUBLE-CHAMBER CAGE CONNECTION TERMINALS.
MADE IN GERMANY
REF: FKM2971P120
The ABB CM-MSS.31S is a thermistor motor protection relay engineered to monitor PTC temperature sensors in electric motors. In marine environments, motor thermal protection is critical — pump drives, ventilation fans, compressors, and auxiliary machinery operate under continuous thermal stress. The CM-MSS.31S works on the closed-circuit principle to detect overtemperature conditions before winding failure or unplanned machinery stoppage at sea, making it a reliable component in motor control centres and auxiliary switchboards across the Business & Industrial marine sector.
Key Features
✓ Wide supply voltage range: 24–240 V AC/DC, 15–400 Hz — compatible with diverse onboard power system configurations
✓ SPDT relay output: 1 N/C + 1 N/O contacts rated at 250 V / 4 A for direct integration with motor control and alarm circuits
✓ Dual sensor circuit fault detection: Monitors for both short-circuit and interrupted-wire conditions in the PTC sensor loop
✓ Flexible reset modes: Automatic, manual, or remote reset available once the fault condition has been cleared
✓ ATEX certified to Directive 94/9/EC: Approved for use in potentially explosive atmospheres including engine rooms and enclosed cargo spaces
Marine Applications
Thermal protection of seawater cooling pump motors and ballast pump drives
Fan motor monitoring in engine room ventilation and HVAC systems
Compressor motor protection in refrigeration plant and air conditioning units
Winch and crane motor protection within deck machinery control panels
Auxiliary machinery motor monitoring in power management and distribution systems
Why Marine Engineers Choose ABB CM-MSS.31S
ABB’s CM-MSS range is a proven standard in industrial and marine motor protection. The CM-MSS.31S combines a wide-range power supply, ATEX certification, and comprehensive sensor circuit diagnostics in a compact DIN-rail format — simplifying inventory management and ensuring regulatory compliance across mixed-voltage vessel installations. Manufactured in Germany to ABB’s industrial quality standards.
Ideal For
Merchant vessels, offshore platforms, naval auxiliary ships, ferry and RoRo operators, dredgers, fishing vessels, and any vessel requiring certified motor thermal protection in motor control centres, auxiliary switchboards, or machinery control panels.
Technical Support & Compliance
We provide complete solutions including remote troubleshooting, onboard support, testing and commissioning, repair, retrofit and upgrade, and system integration support for ABB motor protection relays. Compatibility with your specific motor control system and installation is subject to confirmation — please share nameplate photos, part numbers, wiring drawings, system model and version, vessel name or IMO number, and scope of supply when enquiring to ensure the correct solution is confirmed before dispatch.
