Circuit Breaker Ratings Chart

There are many compliance requirements and application considerations associated with series combination ratings.

Circuit breaker ratings chart.

These conditions per ul 489 underwriters laboratories standard for safety for molded case circuit breakers and circuit breaker enclosures include mounting the cb in free air i e. The circuit breaker also needs to be large enough to support the minimum circuit ampacity which for this example would be a circuit breaker rated for at least 34 amps which means we d jump up to. 10ka bs en 60947 2. During short circuit the cb is not only subjected to thermal.

Series ratings series ratings 03 19 de14 1 selection guide contents description page series ratings nq panelboards 2 nq nf panelboardss 3 i line series connected circuit breaker ratings 4 fuse i line circuit breaker series connected ratings 5 homeline loadcentre single row short circuit current rating 6. Higher short circuit capacities up to 25ka are. Break the circuit from the main supply. The value of short circuit breaking current is expressed in rms.

Breaking capacity bs en 60898. In normal conditions when the circuit current rating is lower than the circuit breaker rating the circuit operation is normal and it can be changed by manual operation. Such impedance is developed directly by the forces of the let through current created when the contacts are blown open. In case of fault or short circuit when the value of current exceeds the circuit breaker current it will automatically trip i e.

With no enclosure where the ambient temperature is held at 40 degrees c approximately 104 degrees f. Some breakers rated 15 to 50 amperes 120 240 volt. The higher the amperage rating of the circuit the larger the wires need to be in order to avoid excess heat that can melt wires and cause fires. Hence short circuit breaking capacity or short circuit breaking current of circuit breaker is defined as maximum current can flow through the breaker from time of occurring short circuit to the time of clearing the short circuit without any permanent damage in the cb.

This page provides resources for evaluating the application of series rated combinations and provides recognized fuse circuit breaker combinations available in listed panelboards or loadcenters. Isobar 4 pan assemblies. Voltage ratings 240 440v ac. N bs en 60898 the m category ratings for short circuit capacities disappear.

The manufacturer must however declare the short circuit capacity of the products at specified power factors of test circuit. Technical data current ratings 1 to 63a at 300c to bs en60898. Miniature circuit breakers ratings 1 to 63a breaking capacity 15ka 12 installation symmetrical din rail.