Circuit breakers

What you should know about circuit breakers. In each distribution board, you will find several circuit breakers of different types and patterns in terms of ampere capacity, type, number of poles, maximum rated current, and short circuit that it can handle.

Therefore, we have come to you with an article supported by a simplified and brief explanation in which it reviews the most important basic points that you should know well about circuit breakers  before choosing.

Circuit breakers

Circuit breakers or  circuit breakers are available  in the market in different types depending on the type of current, protection, number of poles, and rated ampere capacity.

And when we want to protect the distribution board, electrical loads, and people from the leakage current, we need circuit breakers dedicated to protecting against ground leakage, and not to choose the MCB type circuit breakers.

From this point of view, the importance of studying what you should know about  the types of electrical circuit breakers  or circuit breakers, and of course there are some paths during the electrical design that determine the type of circuit breaker to be installed and used as a protection element in distribution panels or electrical installations.

What you should know about circuit breakers

We review with you some of the basic points that you should take into consideration before  choosing an electrical circuit breaker  (current circuit breaker), including:

type of electrical protection

Each type of electrical circuit breaker has its own uses. MCB circuit breakers are used to protect against overloads and short circuits, as well as to protect sub-wiring such as homes, and are available in the market with ampere capacities up to 125 amperes.

While  ground leakage breakers  are used as a protection element against current leakage,  overloads are used  to protect electric motors in particular and electrical loads in general.

Electric breaker type

Electric circuit breakers are available in different types, each of which is used according to the nature of protection and flexibility, as:

• MCB circuit breakers protect electrical loads (end of electrical circuits).
• MCCB Breaker: It is used as a main protection for a distribution board or a sub in case of large loads such as electric submersibles or large pumps.
• RCCB circuit breakers: used to protect against leakage current in the electrical circuit as a result of a malfunction.
• MPCB ​​circuit breakers: They are used to protect electrical loads in general and electric motor loads in particular against a slight increase in current, as well as protection against high short current and against the fall of one of the phases.
• ACB breaker: (breaker) is used to protect the main electrical panels. This type of breaker is flexible and contains many settings. It is more complex and requires special experience to deal with it.

Rated cutter capacity

• It is necessary to determine the rated breaker capacity, by calculating the load current or electrical loads to be connected to the MCB sub-breaker.
• The maximum current capacity of the MCCB is selected based on the total current of the electrical loads fed from the electricity distribution board with a safety factor percentage as per the standard specification of each country.
• The rated overload current capacity shall be selected so that it is the same value as the electrical load current or by adding a safety factor of only 5% above the load current.
• Choose the MCCB breaker if you want flexibility in determining its rated current capacity and short circuit current, and if the load is large or you want to protect a sub or main distribution panel.

Maximum short-circuit current tolerated by the breaker and the cut-off time

• A very important point, and accordingly, the electric cutter is chosen so that it is able to withstand the current of the palace in the event of its occurrence, and disconnect the current immediately in less than a second.
• The maximum short circuit breaker current is selected based on prior studies by specialized engineers on cable tolerance, breaker separation speed, and electrical transformer data (distribution transformer).

The number of electrodes of the circuit breaker

If the breaker is 1 phase main choose 1 or 2 poles as is the case with earth leakage circuit breakers, while if the electricity source is 3 phase choose a 3 phase breaker (each pole to phase) or 4 pole (3 phase RST + Neutral N).

Categories of electric breakers

A very important information that some people may ignore, which is the accuracy of the circuit breaker, as MCB circuit breakers come in several categories: A, B, C, and D.

To know more about the categories or symbols of MCB electrical circuit breakers..