The Siemens SIRIUS 3RN2011-2BW30 is a thermistor motor protection relay designed to monitor PTC thermistor sensors embedded in motor windings. It trips the output when the winding temperature exceeds the sensor's rated response threshold, protecting motors against overheating from overload, stalled rotor, or cooling failure. The relay operates on a 24-240 V AC/DC supply and includes both open-circuit and short-circuit detection in the sensor circuit, so a broken or shorted sensor wire also triggers a safe state — a feature that matters when the motor is in a remote or hazardous area.
Siemens 3RN2011-2BW30 SIRIUS thermistor motor protection rel
MPN3RN2011-2BW30
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Siemens SIRIUS 3RN2 thermistor motor protection relay, 3RN2011-2BW30, rated 24-240 V AC/DC, MTBF 97 a, ATEX approval, open-circuit and short-circuit detection in sensor circuit.
Sourced new & surplus through independent channelsAuthenticity-screened · ESD-safe packingListing updated Jul 2026
Specifications
| Parameter | Value |
|---|---|
| Product function | thermistor motor protection |
| Product designation | Thermistor motor protection relay |
| Product line / brand name | SIRIUS |
| Parameter | Value |
|---|---|
| Rated value (50 Hz) | 24 ... 240 V |
| Rated value (60 Hz) | 24 ... 240 V |
| Parameter | Value |
|---|---|
| Electrical connection type | spring-loaded terminal (push-in) |
| Parameter | Value |
|---|---|
| Ingress protection (IP rating), wired | IP20 |
| Installation altitude, max. | 2 000 m |
| Parameter | Value |
|---|---|
| Fastening method | screw and snap-on mounting onto 35 mm DIN rail |
| Mounting position | any |
| Width | 22.5 mm |
| Height | 100 mm |
| Depth | 90 mm |
| Conductor cross-section, solid | 20 ... 12 |
| Conductor cross-section, finely stranded (with ferrule) | 0.5 ... 2.5 mm² |
| Mounting clearance, top | 0 mm |
| Mounting clearance, rear | 0 mm |
| Mounting clearance, side | 0 mm |
| Mounting clearance, front | 0 mm |
Product details
Frequently asked questions
What is the MTBF of 3RN2011-2BW30?
The listed MTBF is 97 a, with an MTTFd of 303 a.
What supply voltage does 3RN2011-2BW30 accept?
It accepts 24-240 V AC/DC, covering both common control voltages in a single unit.
Does 3RN2011-2BW30 have ATEX approval?
Yes, the design includes ATEX approval and provides open-circuit and short-circuit detection in the sensor circuit.
What is the mounting width of 3RN2011-2BW30?
The width is 22.5 mm, fitting a single DIN-rail module slot.
MPN
3RN2011-2BW30