SIRIUS 3RV2 circuit breakers

The availability of machines and plants is a precondition for maximum productivity. Machines and plants should therefore be reliably protected against overload from the power supply system. In the event of a failure, motor starter protectors quickly disconnect the equipment from the supply, thus preventing expensive damage. The SIRIUS 3RV2 motor starter protector provides ideal protection.

SIRIUS 3RV2 circuit breakers portfolio


Motor protection

SIRIUS 3RV20 motor starter protector

SIRIUS 3RV20 motor starter protectors protect your motor reliably and economically.


  • Available in sizes S00, S0, S2 and S3 from 0.11 to 100 A
  • Bimetals with long-term stability
  • Provides overload and short-circuit protection


Motor protection with overload relay function

SIRIUS 3RV21 motor starter protector

Protects your motor with integral overload relay function. This gives the motor starter protector the option of automatic reset in the event of overload, which supports the trouble-free operation of your plant and increases productivity.


  • Available in sizes S00, S0, S2 and S3 from 0.11 to 100 A
  • Motor starter protector does not shut down in the event of an overload
  • Overload is signaled by laterally mounted 1NO+1NC auxiliary contacts
  • The load feeder must be shut down via a downstream contactor (resetting of the auxiliary contacts)


Starter combination

SIRIUS 3RV23 motor starter protector

Overload relay can be set to "automatic reset", which eliminates the need to open the control panel. Motor starter protector provides short-circuit protection. Overload and short-circuit protection are carried out separately and can also be signaled separately.


  • Available in sizes S00, S0, S2 and S3 from 0.11 to 100 A


Transformer protection

SIRIUS 3RV24 motor starter protector

The SIRIUS 3RV24 motor starter protector provides reliable transformer protection.


  • Available in sizes S00, S0 and S2 from 0.11 to 65 A
  • Optimized for the protection of transformers
  • Response value of the short-circuit release 20 x In


Plant/transformer protection according to UL 489/CSA C22.2 No.5

SIRIUS 3RV27 and 3RV28 circuit breakers – fuseless protection for systems and transformers to UL489/CSA C22.2 No.5

The circuit breakers for use in UL markets. SIRIUS 3RV27 and 3RV28 can be used according to UL 489/CSA C22.2 No.5.


  • Use as "branch circuit protection device" (BCPD) acc. to UL/CSA
  • For fuseless protection of systems, motors and non-motor loads (e.g. transformers)
  • In sizes S00 and S0 up to 22 A, switching capacity 65 kA or 50 kA at 480 Y/277 V
  • In size S3 up to 70 A, switching capacity 65 kA at 480Y/277V, or up to 30 A 65 kA at 480 V
  • Type testing in accordance with IEC 60947-2
  • Standardized configuration of control panels in accordance with IEC and UL/CSA


Now also insertable in 3RV29 infeed system.

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Problem solver for 1-, 2- and 3-phase applications

Circuit breakers SIRIUS 3RV20(…)-0DA0 for plant protection and SIRIUS 3RV24(…)-0DA0 for transformer protection

Circuit breakers SIRIUS 3RV20(…)-0DA0 for plant protection and SIRIUS

3RV24(…)-0DA0 for transformer protection

  • For the protection of 1-, 2- and 3-phase applications such as air conditioners, fans and power supplies 
  • Without phase imbalance and phase failure detection IEC approval (use 3RV27/28 for UL / CSA applications) 
  • Application e.g. for charging infrastructure AC charging (e-cars) 
  • Can be used in the 3RV29 infeed system 
  • Very high short-circuit breaking capacity

Highlights at a glance

Why are motor starter protectors/circuit breakers so important?


They protect motors and starters and so they also protect your machines and plants. As a result, you avoid unnecessary production downtimes and possible serious consequences arising from defective equipment or fire damage.


Take advantage of the benefits of SIRIUS 3RV2 motor starter protectors


SIRIUS 3RV2 motor starter protectors reliably intervene in three different cases. In the event of a short-circuit – current >13 times the rated current – the short-circuit releases isolate the faulty load feeder from the power supply within only a few milliseconds. Greater damage, caused by fires for example, can thus be avoided. The motor starter protector features a lockable operating mechanism for manual closing/opening, to be used for example while carrying out repairs.


The overload release isolates the load from the power supply if it is loaded with an overcurrent for a certain time. Tripping is based on a specific time-current characteristic. This prevents possible damage to the load and the system.


The overload release also trips in the event of phase failure or extreme phase unbalance.


SIRIUS 3RV2 motor starter protectors are part of SIRIUS Control, one of the four pillars of the SIRIUS portfolio.

Accessories for the circuit breaker - Door-coupling rotary operating mechanisms

Motor starter protectors/circuit breakers with a rotary operating mechanism can be mounted in a control cabinet and operated externally by means of a door-coupling rotary operating mechanism. When the cabinet door with motor starter protector is closed, the operating mechanism is coupled. When the motor starter protector closes, the coupling is locked which prevents the door from being opened unintentionally.