Ziehl – MSF220SE – PTC Resistor Trip Relay, 2-Channel, 24-240 V AC/DC

The MSF220SE by Ziehl is a 2-channel PTC resistor temperature protection relay designed to monitor winding temperature in electrical machines. It provides early warning and alarm outputs, with built-in delay to suppress spurious triggers on power-up. The unit supports PTC sensors in series (1 to 6 per channel) and features two changeover (CO) relay outputs plus a time-delayed auxiliary relay for smooth operation.