In which applications are the undervoltage trip releases with early make contacts used?

This type of undervoltage trip release has the purpose of removing voltage from the coil of the release itself when the motor protection circuit breaker is in OFF position. Otherwise the coil would remain permanently powered even if with the machine is stopped. Turning off the power supply to the undervoltage trip release reduces unnecessary [...]

Which is the motor protection circuit breaker behaviour in case of phase loss?

Phase failure is a fault condition that can cause damage to the three-phase motor. The Lovato motor protection circuit breakers, SM series, are sensitive to phase failure and therefore save the motor from damages caused by this condition. It is possible to have two situations: phase failure at motor starting and phase failure when the [...]

By |2021-01-04T11:19:37+02:00January 4th, 2021|, |Comments Off on Which is the motor protection circuit breaker behaviour in case of phase loss?

In the technical data of the motor protection circuit breakers, what does “utilization category: A” mean?

The category of use of a circuit breaker is defined by the product standard IEC/EN60947-2. This standard indicates 2 categories: A and B. Category A includes circuit-breakers without intentional tripping delays in the event of a shortcircuit, while category B includes circuit breaker with intentional tripping delays to guarantee selectivity. The motor protection circuit breakers [...]

By |2021-01-04T11:20:15+02:00January 4th, 2021|, |Comments Off on In the technical data of the motor protection circuit breakers, what does “utilization category: A” mean?

Is it possible to use the motor protection circuit breakers to protect single-phase motors?

Yes, but a simple trick in the wiring must be implemented, that is, have the current pass through the three phases of the motor protection switch. In practice, a phase must pass through two poles of the switches connected in series between them. Otherwise the motor protection switch will trip off due to thermal intervention. [...]

By |2021-01-04T15:14:46+02:00December 18th, 2020|, |Comments Off on Is it possible to use the motor protection circuit breakers to protect single-phase motors?