Contactors, Relays & Motor Starter Protectors
Siemens offers a wide of protection equipment for motor protection including thermal and solid-state, overload relays to circuit breakers for any application you may need.
SIRIUS overload relays, can be used in many applications, even those used in explosive environments. These screw-type, spring-loaded or ring cable lug connections protect loads as well as other switching and protective against overload, phase asymmetry and phase failure, and can easily be used with the contactors of the SIRIUS module kit.
There are two versions of overload relays:
- Thermal overload relays using bimetals
- Electronic overload relays using current transformers
SIRIUS 3RB3 Electronic Overload Relays
SIRIUS 3RB30 electronic overload relays for standard applications are responsible for current-dependent overload protection of electrical loads (e.g. motors). Due to the wide current setting ranges and various tripping characteristics, this complete series of motors are covered with just a few different options. The 3RB31 version offers enhanced functions including, but not limited to: integrated, electrical remote reset or ground fault detection.
SIRIUS 3RB2 Electronic Overload Relays
For demanding applications, the modular variants of the 3RB22, 3RB23 or 3RB24 electronic overload relays offer full motor protection using connected thermistors to sense the motor temperature, comprehensive display and signaling functions, and a communication link using IO-Link.
SIRIUS 3RU Thermal Overload Relays
Responsible for current-dependent overload protection of electrical loads (e.g. motors), in the main circuit. The 3RU2 overload relays are available with spring-loaded, screw-type and ring cable lug connections, for flexible and cost-effective implementations.
SIRIUS 3RV Motor Starter Protectors
SIRIUS 3RV motor starter protectors are compact, current-limiting circuit breakers up to 100 A for motor or starter protection. They guarantee safe disconnection in the event of a short circuit and protect loads and the system from overload. They are also suitable for normal switching duty with loads that have a small number of switching operations as well as for reliable isolation of the equipment from the supply system.