ABB 1SVR550805R9300 CM-MSE Thermistor Motor Protection Relay 1NO 24VAC Relay for Thermistor Protection (PTC)

The ABB CM-MSE (SKU: 1SVR550805R9300) is a thermistor motor protection relay (PTC) designed to protect electric motors from overtemperature damage by monitoring PTC thermistor sensors embedded in the motor windings. Rated at 4 A / 250 V with a 24 VAC supply and a single normally-open (1NO) output contact, the CM-MSE delivers reliable thermal protection in compact 22.5 mm DIN-rail format for control panels and industrial automation systems.

Technical Specifications

Certifications & Standards

• UL 508: Listed for industrial control equipment (USA)
• cUL: Canadian UL recognition for industrial control use
• CSA: Certified to Canadian Standards Association requirements
• CE: Compliant with EU directives for electrical safety and EMC
• UKCA: UK Conformity Assessed for post-Brexit Great Britain market
• CCC: China Compulsory Certification for import and sale in China
• RoHS: Compliant with EU Restriction of Hazardous Substances Directive
• REACH: Compliant with EU REACH chemical safety regulation

Applications & Use Cases

• Motor thermal protection in industrial drives and motor starters
• Integration with PTC thermistor sensors embedded in motor windings
• Control panel automation circuits requiring compact DIN-rail mounting
• HVAC, pump, compressor, and conveyor motor protection
• OEM machinery requiring UL508 / CSA certified thermistor monitoring relays

Frequently Asked Questions

What sensor type does the CM-MSE work with?
The CM-MSE is designed exclusively for PTC (Positive Temperature Coefficient) thermistors embedded in motor windings, triggering the output contact when sensor resistance indicates an overtemperature condition.

What is the supply voltage of the CM-MSE?
The relay for thermistor protection CM-MSE operates on a 24 VAC control supply voltage.

What output configuration does the CM-MSE provide?
It provides one normally-open (1NO) output contact rated at 4 A / 250 V for integration into motor control or alarm circuits.