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ABB CM-MSS.23P (1SVR740700R2200) thermistor motor protection relay with 110–130 V AC or 220–240 V AC control supply, one PTC sensor circuit, automatic, manual or remote reset, closed-circuit operation, two changeover contacts rated at 250 V / 4 A and Easy Connect push-in terminals for industrial motor winding temperature protection.
£58.39
The ABB CM-MSS.23P (1SVR740700R2200) is a reliable thermistor motor protection relay designed to monitor electric motor winding temperatures and help protect industrial motors against overheating. Part of ABB's CM-MSS measuring and monitoring relay range, it evaluates signals from built-in PTC thermistor sensors to detect excessive motor temperatures caused by overload, insufficient cooling or demanding operating conditions.
The CM-MSS.23P operates from a selectable 110–130 V AC or 220–240 V AC control supply and features one PTC thermistor sensor circuit. It provides two changeover (SPDT) output contacts rated at 250 V / 4 A, allowing motor temperature faults to be communicated to contactors, PLC inputs and industrial alarm systems.
With configurable automatic, manual or remote reset, closed-circuit operation and ABB's maintenance-free Easy Connect push-in terminals, the CM-MSS.23P offers flexible integration into industrial motor control applications. Its compact 22.5 mm DIN rail housing makes it suitable for motor control centres, machinery panels and automation cabinets where reliable thermal protection and efficient installation are important.
The ABB CM-MSS.23P monitors the resistance of PTC thermistor sensors embedded within electric motor windings. When the motor temperature approaches the thermistor's specified response temperature, sensor resistance increases sharply. The relay detects this change and switches its output contacts to indicate an overheating condition.
Unlike motor protection methods based exclusively on current measurement, PTC thermistor monitoring responds to the actual thermal condition of the motor windings. This makes it particularly useful for identifying overheating associated with heavy-duty starting, frequent switching, elevated ambient temperatures, insufficient cooling or mechanical operating problems.
The CM-MSS.23P provides one PTC sensor measuring circuit and operates according to the closed-circuit principle. During normal operation, the output relay remains energised. When a monitored temperature fault occurs, the output changes state, enabling a correctly designed control circuit to disconnect the motor, activate an alarm or notify a PLC.
Its two changeover output contacts allow the thermal protection signal to be incorporated into industrial control and monitoring arrangements. One contact may be used for a motor contactor control circuit while the other provides a separate indication, provided the installation follows the manufacturer's contact ratings and wiring requirements.
The ABB CM-MSS.23P supports automatic, manual and remote reset after the monitored motor temperature has returned to an acceptable condition.
With automatic reset, the relay can return to its normal state once the overheating condition clears. Manual reset requires operator intervention using the front-mounted reset button, while remote reset allows the relay to be reset through a suitable external control arrangement.
The appropriate reset function should be selected according to the machine's operating requirements and safety assessment. Where unexpected motor restarting could create a hazard, the complete control system must incorporate suitable restart prevention, interlocking and protective measures. The reset function of the thermistor relay alone does not replace a machinery safety control system.
The CM-MSS.23P features ABB's Easy Connect Technology, using push-in terminals instead of conventional screw connections. This allows suitable conductors to be connected securely through a spring-clamp mechanism, simplifying electrical panel wiring and reducing the need for routine terminal retightening.
Combined with its 22.5 mm DIN rail housing, the push-in terminal design makes the CM-MSS.23P particularly suitable for OEM equipment, production machinery and industrial automation panels where consistent wiring quality and efficient installation are important.
The relay is designed according to IEC 60947-8 and incorporates overvoltage-protected supply and measuring inputs. Correct sensor selection, wiring and protective device coordination remain essential for reliable operation.
Tick the specs you need, then view products that match.
| Monitoring Function | Temperature / thermistor | |
|---|---|---|
| Reset Type | Manual or automatic |
The ABB CM-MSS.23P is a thermistor motor protection relay designed to monitor motor winding temperature using built-in PTC thermistor sensors. It helps protect electric motors against overheating caused by overload, insufficient cooling and abnormal operating conditions.
The CM-MSS.23P, ABB order code 1SVR740700R2200, operates from a rated control supply voltage of 110–130 V AC or 220–240 V AC. These are the specified AC supply ranges for this model.
No. The CM-MSS.23P is specified for 110–130 V AC or 220–240 V AC. For applications requiring a 24 V AC/DC control supply, the ABB CM-MSS.22P is the corresponding push-in terminal version.
The relay uses PTC thermistor temperature sensors installed within motor windings. It monitors changes in sensor resistance to detect excessive motor temperatures and is not intended as a general-purpose Pt100 or thermocouple temperature controller.
The CM-MSS.23P features one PTC thermistor measuring circuit. This circuit monitors compatible motor temperature sensors and provides a relay switching response when an overheating condition is detected.
Yes. The relay supports automatic, manual and remote reset after the temperature fault condition has cleared. A front-mounted reset button provides local operation, while remote reset allows integration with an external control circuit.
The relay provides two changeover (SPDT) output contacts rated at 250 V / 4 A. These contacts can be used for suitable motor contactor control circuits, PLC inputs and industrial alarm signalling.
Under the closed-circuit principle, the output relay is energised during normal, healthy operation and changes state when a detected fault causes it to release. This supports dependable signalling of motor overheating conditions.
The CM-MSS.23P uses ABB Easy Connect push-in terminals. These screwless spring-clamp connections simplify installation and provide secure, maintenance-free electrical connections when correctly wired.
Both models operate from 110–130 V AC or 220–240 V AC and provide one PTC sensor circuit, two changeover contacts and configurable reset functions. The main difference is the terminal technology: the CM-MSS.23P uses push-in terminals, while the CM-MSS.23S uses screw terminals.
Both relays provide PTC motor temperature monitoring, two changeover contacts, configurable reset functions and push-in terminals. The main difference is the control supply voltage: the CM-MSS.22P operates from 24 V AC/DC, while the CM-MSS.23P operates from 110–130 V AC or 220–240 V AC.
No. The CM-MSS.23P provides temperature-based motor protection using PTC thermistors. It does not replace appropriately rated short-circuit protection, electrical overload protection or other protective devices required by the installation.
The relay is designed for DIN rail mounting inside industrial motor control panels, automation cabinets and electrical enclosures. Its compact 22.5 mm housing width and Easy Connect push-in terminals support efficient installation.
ABB CM-MSS thermistor motor protection relays provide dependable temperature-based protection for industrial electric motors. With PTC winding temperature monitoring, automatic, manual or remote reset, closed-circuit operation and two changeover contacts, the CM-MSS.23P offers a practical solution for detecting motor overheating. Its dual AC control supply ranges, Easy Connect push-in terminals and compact DIN rail housing make it suitable for modern industrial motor control and automation systems.
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