ABB – CM‑MSS (1SVR430811R1300) – Thermistor Motor Protection Relay, 220‑240 VAC

The ABB CM‑MSS (1SVR430811R1300) is a DIN-rail motor protection relay that monitors winding temperature via PTC thermistor sensors. Designed for single-motor protection, it offers reliable overload protection by opening its 2 SPDT contacts when the PTC sensor exceeds ~2.7 kΩ, with shorted/broken sensor detection. Ideal for industrial motors, pumps, or HVAC systems.

 Key Features & Specifications

• Model / P/N: CM‑MSS / 1SVR430811R1300  

• Supply Voltage: 220–240 VAC ±10%, 50/60 Hz  

• Control Supply Range: 24–240 VAC/DC series also exists; this one is specifically 220–240 VAC  

• Sensor Circuit: Monitors single PTC sensor; trips above ~2.7 kΩ, resets below ~1.6 kΩ  

• Sensor Fault Detection: Detects short-circuit (<20 Ω) or open circuit, indicated by flashing red LED  

• Output Contacts: 2 × SPDT (form C); rated 4 A @ 250 VAC

• Reset Options: Manual front-button, auto-reset, or remote reset via terminal

• LED Indicators: Green = supply OK; Red = fault  

• Mounting & Dimensions: 22.5 mm wide (1 module), 85.6 × 103.7 × 22.5 mm; ~0.15 kg  

• Approvals: UL 508, CSA, GL, GOST, CE; thermal & phase safety per IEC/EN 60947‑8  

• Durability: Engineered for continuous motor operation; used and new units available on eBay around USD 60–100