Why Choose the ABB CM-MSS.13P Thermistor Motor Protection Relay?
The ABB CM-MSS.13P (1SVR740700R2100) is a compact, 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 PTC thermistor sensors installed within motor windings to detect excessive temperatures caused by overload, insufficient cooling or demanding operating conditions.
The CM-MSS.13P operates from selectable 110–130 V AC or 220–240 V AC control supplies at 50/60 Hz. It features one PTC thermistor measuring circuit and one changeover (SPDT) output contact rated at 250 V / 4 A. Its automatic reset function allows the relay to return to normal operation after the monitored temperature fault has cleared.
Designed according to IEC 60947-8, the CM-MSS.13P uses the closed-circuit operating principle and incorporates overvoltage-protected supply and measuring inputs. ABB's maintenance-free Easy Connect push-in terminals and compact 22.5 mm DIN rail housing make it particularly suitable for industrial control cabinets, motor control centres and OEM machinery.
Key Advantages
- Reliable motor winding temperature protection using PTC thermistor sensors.
- Helps detect overheating caused by overload, inadequate ventilation and insufficient cooling.
- Dual AC control supply ranges: 110–130 V AC or 220–240 V AC.
- One PTC thermistor measuring circuit for direct thermal supervision.
- One changeover (SPDT) output contact rated at 250 V / 4 A.
- Automatic reset after the monitored temperature fault has cleared.
- Closed-circuit operating principle for dependable fault signalling.
- ABB Easy Connect push-in terminals simplify panel wiring.
- Maintenance-free spring-clamp connections reduce routine terminal maintenance.
- Overvoltage-protected supply and measuring inputs support reliable operation.
- Designed according to IEC 60947-8.
- Compact 22.5 mm housing width helps conserve control cabinet space.
- Tool-free DIN rail mounting and removal.
- Flame-retardant housing material classified UL 94 V-0.
- Suitable for industrial motor control, automation and machinery applications.
- Optional sealable transparent cover helps prevent unauthorised adjustments.
Key Features
- ABB CM-MSS.13P thermistor motor protection relay.
- Manufacturer order code: 1SVR740700R2100.
- Rated control supply voltage: 110–130 V AC / 220–240 V AC.
- Rated supply frequency: 50/60 Hz.
- Monitoring function: Motor winding temperature protection.
- Sensor technology: PTC thermistors.
- Number of measuring circuits: 1.
- Reset function: Automatic reset.
- Operating principle: Closed-circuit principle.
- Output configuration: 1 changeover (SPDT) contact.
- Output contact rating: 250 V / 4 A.
- Terminal technology: Easy Connect push-in terminals.
- Connection method: Screwless spring-clamp connection.
- Overvoltage-protected supply and measuring inputs.
- LED indication for operating and relay status.
- Product standard: IEC 60947-8.
- Housing width: 22.5 mm.
- DIN rail mounting for industrial electrical panels.
- Optional sealable transparent protective cover.
Technical Specifications
- Manufacturer: ABB
- Product series: CM-MSS
- Model: CM-MSS.13P
- ABB order code: 1SVR740700R2100
- ABB product group: 310921-Measuring & Monitoring Relays
- Product type: Thermistor motor protection relay
- Rated control supply voltage: 110–130 V AC / 220–240 V AC
- Supply type: AC
- Rated supply frequency: 50/60 Hz
- Monitoring function: Motor winding temperature monitoring
- Temperature sensor type: PTC thermistors
- Number of sensor circuits: 1
- Reset mode: Automatic
- Operating principle: Closed-circuit principle
- Output contacts: 1 changeover (SPDT)
- Contact rating: 250 V / 4 A
- UL/CSA contact rating: B300
- Maximum UL/CSA output operating voltage: 300 V AC
- Terminal type: Easy Connect push-in terminals
- Connection technology: Screwless spring-clamp connection
- Input protection: Overvoltage-protected supply and measuring inputs
- Applicable product standard: IEC 60947-8
- Housing protection rating: IP50
- Terminal protection rating: IP20
- Housing flammability classification: UL 94 V-0
- Mounting type: DIN rail mounting
- Operating ambient temperature: −25 to +60 °C
- Storage temperature: −40 to +85 °C
- Dimensions (H × W × D): 85.6 × 22.5 × 103.7 mm
- Product net weight: 0.147 kg
- EAN: 4013614496592
- Customs tariff number: 85364900
Reliable PTC Thermistor Motor Temperature Protection
The ABB CM-MSS.13P monitors the resistance of PTC thermistor sensors installed within electric motor windings. When the winding temperature approaches the thermistor's rated response temperature, sensor resistance increases sharply. The relay detects this change and switches its output contact to indicate an overheating condition.
Unlike conventional current-based motor protection alone, PTC thermistor monitoring responds to the actual thermal condition of the motor windings. This makes it useful for detecting overheating caused by excessive mechanical loading, frequent starting, blocked ventilation, high ambient temperatures or other operating conditions that increase motor temperature.
The CM-MSS.13P provides one PTC sensor measuring circuit and one changeover output contact. This arrangement enables the temperature protection signal to be incorporated into a suitable motor contactor circuit, PLC input or industrial alarm system.
The relay operates according to the closed-circuit principle. During normal, healthy operation, the output relay is energised. When a monitored temperature fault occurs, the output changes state, allowing the connected control system to respond.
For reliable operation, the connected PTC thermistor sensors must be compatible with the relay's measuring characteristics and installed according to the motor manufacturer's instructions.
Automatic Reset for Motor Temperature Monitoring
The CM-MSS.13P features automatic reset. After an excessive motor temperature condition has been detected, the relay returns to its normal operating state when the PTC thermistor resistance falls back below the applicable reset level.
This functionality can be useful in industrial control systems where automatic restoration of the monitoring relay is appropriate after the motor has cooled. It also reduces the need for an operator to manually reset the monitoring device after every thermal event.
Automatic relay reset must not be confused with permission for automatic motor restarting. If unexpected restarting could create a hazard, the motor control system must incorporate suitable restart prevention, interlocking and other protective measures.
The CM-MSS.13P is an automatic-reset model. Applications requiring selectable manual or remote reset should use an appropriately specified ABB thermistor motor protection relay instead.
Dual AC Supply Ranges for Industrial Control Systems
The ABB CM-MSS.13P is designed for 110–130 V AC or 220–240 V AC control supplies at 50/60 Hz. These two rated supply ranges make the relay suitable for industrial installations using common AC control voltages.
The supply specification is particularly important when selecting a replacement monitoring relay. The CM-MSS.13P is not a universal 24–240 V AC/DC model and is not specified for direct operation from a 24 V DC control supply.
Its single changeover contact provides a convenient switching interface for motor contactor control circuits and industrial fault signalling, subject to the applicable contact rating and installation requirements.
Easy Connect Push-In Terminals and Compact DIN Rail Installation
The CM-MSS.13P features ABB's Easy Connect Technology, using screwless push-in terminals rather than conventional screw connections. This supports secure, maintenance-free electrical connections when the correct conductor types and installation procedures are used.
The push-in terminal design simplifies control cabinet wiring and helps reduce installation time. It is particularly useful for OEM equipment, industrial machinery and automation panels where efficient assembly and consistent connection quality are important.
With dimensions of 85.6 × 22.5 × 103.7 mm, the relay occupies only 22.5 mm of DIN rail width. Tool-free mounting and removal further support straightforward installation and maintenance.
The housing material is classified UL 94 V-0, while the device incorporates overvoltage-protected supply and measuring inputs. An optional sealable transparent cover is available to help prevent unauthorised changes.
Typical Applications
- Motor winding temperature protection in industrial machinery.
- Thermal monitoring of motors equipped with PTC thermistors.
- Industrial motor control centres and electrical cabinets.
- Pump motor overheating protection.
- Fan and ventilation motor temperature supervision.
- Compressor motor thermal protection.
- Conveyor and material handling equipment.
- Manufacturing and production machinery.
- Industrial motors subject to frequent starting and stopping.
- Motor temperature monitoring in high ambient temperature environments.
- PLC-based motor fault monitoring and alarm signalling.
- Industrial control systems using 110–130 V AC supplies.
- Industrial control systems using 220–240 V AC supplies.
- OEM machinery requiring compact DIN rail motor protection.
- Applications where automatic reset is appropriate.
- Control panels requiring maintenance-free push-in terminals.
