The symbol for circuit breaker.

The symbol for circuit breaker is a schematic representation of a circuit breaker. Instead of putting a picture of a circuit breaker on a drawing, you put a symbol to represent it.

why are circuit symbols used.

Circuit symbols make communication easy. In short, a circuit symbol is a language that is used in engineering to communicate. In engineering, when you want to make a car or an electrical machine.

You design the machine before making it. Many are the times that you would like to share notes with your colleagues.

You simply send the designs to them. When they make some observations they communicate back to you.

Circuit symbols are a universal way of communicating. I may have a colleague who does not speak my local language. But if he knows how to interpret circuit symbols, I will communicate effectively with him.

Why are circuit symbols used?

  1. They make communication easy
  2. make it easy to make electrical and electronics drawings
  3. Circuit symbols make it easy to understand complex designs.
  4. The use of circuit symbols makes it easy for engineers, technologist technicians and craftsmen from different parts of the world to collaborate, communicate and share ideas.

Now that you know why circuit symbols are used, let us dive into a look at some circuit symbols for circuit breakers.

MCB,MCCB and OCB oil circuit breaker.

 An oil circuit breaker is a type of circuit breaker that uses insulating oil as an arc quenching medium. Once the fault occurs within the system, the circuit breaker contacts will be separated and the arc will be struck between the contacts. 

A moulded case circuit breaker (MCCB) is a type of electrical protection device that is used to protect the electrical circuit from excessive current, which can cause overload or a short circuit. With a current rating of up to 2500A.MCCBs are used instead of miniature circuit breakers (MCBs) in large scale power systems for system isolation and protection purposes.

MCB stands for Miniature Circuit Breaker. It automatically switches OFF electrical circuits during any abnormal condition in the electrical network such as overload and short circuit conditions. The MCB is an electromechanical device that guards the electric wires and electrical appliances against overcurrent so as to avoid any kind of fire or electrical hazards.

Handling MCB is quite safer and it quickly restores the supply. When it comes to house wiring applications, MCB is the most preferred choice for overload and short circuit protection. MCB can be reset very fast and don’t have any maintenance cost.

Triple pole and double pole symbol for circuit breaker.

The three-pole circuit breaker operates via the same method as a single-pole breaker. The difference is found in the number of conductors that are connected, or bridged, by the three-pole breaker.

Used most often in a three-phase electrical system, a three-pole breaker connects three different conductors, such as is often used by heavy-duty industrial motors. When a surge exists anywhere in the system, across one or more of the conductors, the breaker trips, and the circuit opens.

Double-pole breakers have two hot wires that are connected by a single neutral wire. That means if there’s a short circuit on either of the poles’ hot wires, both trip.

Cartrige and Isolator symbol for circuit breaker.

Isolator or disconnectors, as the name indicates, is a switching or isolation device, intended to disconnect equipment or electrical Circuit from the supply. It is an offload device, which means it can be operated only when the current passing through it is zero. Unlike circuit breakers, it lacks a built-in arc suppression system. It can be operated only during offload conditions.

The main purpose of using an isolator is to ensure safety during maintenance. Before operating an isolator it is made sure that the current flowing through it is zero or within safety limits. The Breaking capacity of isolators is very less.

Cartridge circuit breakers are cylindrical in shape and have contact points at each end. They are rated for circuits over 30 amps and typically 240 volts. There are two basic types of cartridge fuses. Ferrule-type fuses are rated up to and including 60 amps. They have a cylindrical metal cap on each end and look like big versions of the fuses you find inside the plug end of holiday lights. The knife-blade cartridge fuse is the big brother to the ferrule-type. It is similarly shaped but has a flat metal blade on each end. Knife-blade fuses are used to protect circuits above 60 amps up to 600 amps.

Vacuum and Air circuit breaker.

The symbol for circuit breaker.

A vacuum circuit breaker is a type of circuit breaker where the arc quenching takes place in a vacuum medium. The operation of switching on and off current-carrying contacts, and related arc interruption takes place in a vacuum chamber in the breaker which is called a vacuum interrupter.

An air Circuit Breaker (ACB) is an electrical device used to provide Overcurrent and short-circuit protection for electric circuits over 800 Amps to 10K Amps. 

An air circuit breaker is a circuit operation breaker that uses air as an arc extinguishing medium, at a given atmospheric pressure. 

Final thoughts on the symbol for circuit breaker.

I know there are a lot of symbols for a circuit breaker, but I thought these 8 symbols for a circuit breaker are the most common ones. What other circuit symbols do you know for a circuit breaker?

Share them with me in the comments section below.

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