Motor Circuit Protector Vs Breaker

Circuit breakers which are called mcps or motor circuit protectors are sized with the intent to provide only short circuit and ground fault protection for the motor branch circuit protection per 430 52.

Motor circuit protector vs breaker.

Ul 1077 supplementary protectors. The table will give you the size of the short circuit protection as a percentage of the full load current. Ul 489 circuit breakers. Other means such as overload relays provide the motor overload protection.

Protection against electrical faults such as short circuits line to ground faults and line to line faults. Capacity given in the table for the motor starter protectors the motor starter protector must be protected by a backup fuse. Eaton s motor circuit protectors are ul recognized instantaneous only breakers for motor short circuit protection. This table is used to size the short circuit protection check the motor data sheets for the motor s full load current.

The mpcb can interrupt any electrical fault that is. Ul 489 circuit breakers are intended for installation in a circuit breaker enclosure or as parts of other devices such as service entrance equipment and panelboards they are regularly required on panel designs per the national electrical code. Locate where your motor falls in table 430 52 based on the full load current and motor size. See the following table for the maximum reated current for the backup fuse.

With a backup fuse according to the table the maximum short circuit current is permitted to equal the rated breaking capacity of the backup fuse. The difference between circuit breakers and supplementary protectors. When used in tested motor starter combinations they provide complete ul listed motor control and protection and short circuit current ratings up to 100 000a. Typical thermal magnetic circuit.

Motor circuit protectors motor circuit protectors provide short circuit protection for individual motor loads and are available for a wide range of motor sizes and installation types.