Motor protection circuit breakers act as protection devices for electric motors, monitoring the electrical supply in motor circuits of 50-60Hz. They protect against phase unbalances and losses, which are detrimental to motors, offer protection against current overload, and prevent short circuits.
What are motor protection circuit breakers used for? Motor protection circuit breakers are useful in industrial and building applications such as chillers, compressors, heat pumps and cooling towers, to prevent damages from short circuits or power surges. In the manufacturing industry, circuit breakers interrupt electrical faults below the breaking capacity, which protects machinery and equipment from blowouts.
Types of motor protection circuit breakers Motor protection circuit breakers come in A type or B type classifications, dependent on utilisation and function.
The A type breaker is not explicitly intended for selectivity and does not allow intentional short time delay under short circuit conditions.This means that the system interrupts immediately when current or voltage levels match the breaking capacity.
Type B breakers allow for an intentional and adjustable short time delay under short circuit conditions, which enables the system to continue for a short while with currents exceeding breaking capacity levels.
Description:
The ABB MS132 series of manual motor starters
are compact highly reliable devices used to manually switch on and off motors. The MS132 series protects the motors reliably, without the need for a fuse, from short-circuits, overload and phase failures. Short-circuit protectionOverload protectionTrip class 10 APhase loss sensitivityON/OFF switching functionalityDisconnecting ...
Description:
Maximum rated current 100A (45kW @ 400V a.c.)Rated
operational voltage: 690VShort-circuit proof to 50kA @ 400V a.c.Maximum switching frequency; 15 operations/hourMechanical life; 105 operationsAmbient temperature range; –20 to +60 ° CLong term stabilityManual resetLockable in off position.
Description:
Overload protection compensated -5 to +40°CLockable in 'OFF'
positionShort circuit protection, therefore, no back-up fuse protection is required where the prospective fault level is less than the breaking capacity of the unitExpected life cycles 0.1 x 106Maximum switching frequency 40 operations/ hourAmbient temperature (min/max) -25 to +55°C (open) and up ...
Description:
Siemens 3RV10 and 3RV13 moulded case circuit breakers
are compact, current limiting motor starter protectors which can be used in motor feeders for special voltages of 440V, 480V, 550V and 690V. They are used for switching and protecting induction motors and other loads with rated currents up to 800A.For motor ...
