Work according to the closed circuit current principle (monostable design) and therefore self-monitoring with regard to wire breakage
Triggered when control voltage fails
Electrical separation for devices with AC control voltage
Overall width of 22.5 mm
Screw connection

3RN1 thermistor motor protection devices are thermal protection devices that are suitable, in combination with type A PTC resistors (cold conductors), for monitoring the temperature of electrical drives, transformer windings, oils, bearings, air etc.

EN 50081-2, EN 50082-2 and DIN VDE 0660 Parts 302 and 303 and IEC 34-11-2 Section 1 and 2

!!! Phase-out product !!! This product is in obsolescence mode and is due for discontinuation by the manufacturer. We recommend that you review the preferred successor proposed by the manufacturer: 175-2281 (3RN2011-1BA30)

Siemens 3RN1 Thermistor Relays

3RN1 thermistor relays are a range of thermal protection devices, which when used in conjunction with external PTC thermistors, offer temperature monitoring of electrical drives, transformers and other critical components such as bearings. The 3RN1 range operates on the principle of closed-circuit current and are therefore self monitoring in the event of sensor wire breakage.