Motor Protection Circuit Breakers

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.