3RN1 thermistor motor protection relays offer substantial advantages wherever current-dependent protection with circuit-breakers or overload relays is simply not enough: in certain situations overheating of a motor may occur, which won't be detected by the thermal image in the circuit breakers or overload relays.

Applications

• Heavy starting (e.g. centrifuges)
• Frequency converters
• Frequent switching
• Impeded cooling, e.g. due to soiled environment (paper and textile industry, cement works)
• Braking operations
• "Warning and tripping" function by using two sensor circuits with different response temperatures in order to be able to react before shutdown (e.g. switch in additional cooling, reduce load)
• Multimotor protection with a single device, e.g. for conveyor lines where several motors need to be switched off simultaneously

SIRIUS 3RR2 and 3UG4 Monitoring Relays.

SIEMENS monitoring relays reliably protect against consequential damage caused by mains, voltage or temperature faults. Additionally, SIRIUS 3UG monitoring relays offer freely parameterizable threshold values and functions, deliver a clear diagnosis and can even correct a false phase sequence on their own. The advantages: Production errors can be avoided in a targeted manner. Availability and productivity are increased sustainably.

With the SIRIUS 3UG4 monitoring relay, power system and voltage faults can be identified and rectified at an early stage, before extensive damage occurs. The relays allow for the individual assignment of parameters as well as distinct diagnostics.

The SIRIUS 3RR2 monitoring relay, which is simply plugged into a contactor, not only serves the monitoring of motors or other consumers, but rather protects your entire application. SIRIUS 3RR2 offersfast diagnostics thanks to clear error messages at the display.

The relays SIRIUS by Siemens offer maximum machine and system protection and now - thanks to IO-Link - also communicate with the control level. Enjoy greater flexibility with the monitoring relays SIRIUS for IO-Link: In addition to the unchanged autonomous monitoring function, measured values and data can directly be transmitted to the control via IO-Link. Also parameter assignment can either be done locally or via IO-Link. Benefit from considerably simplified device replacement - thanks to data synchronization and automatic parameter assignment via parameter server.

Available with IO-Link connection:

SIRIUS 3UG48 for IO-Link: for the monitoring of electrical and mechanical parameters.

SIRIUS 3RR24 for IO-Link: for the monitoring of 3-phase currents - directly integrated in the motor feeder.

SIRIUS 3RS Temperature Monitoring Relays

The temperature monitoring relays SIRIUS by Siemens support you in protecting your plant the best possible way.

They monitor HVAC systems just as reliably as control cabinets or motors - if necessary with up to three sensors at a time. If the measured temperature lies above or below a certain critical value or leaves a specific operating range, the output relay either switches on or off at these threshold values - depending on the assigned parameters.

By detecting sensor wire break and short-circuit, our temperature monitoring relays allow for a quick error diagnostics at any given time.

The temperature monitoring relays SIRIUS are now also available for IO-Link - for seamless industrial communication.

In addition to the unchanged autonomous monitoring function, measured values and data can directly be transmitted to the control via IO-Link. Also parameter assignment can either be done locally or via IO-Link. Benefit from considerably simplified device replacement - thanks to data synchronization and automatic parameter assignment via parameter server.