What Is the Difference Between AC MCB And DC MCB?

08th Feb 2022

If you’re trying to find out the differences between AC MCBs and DC MCBs, you’ve come to the right place. MCB stands for miniature circuit breaker. It is used to protect electrical appliances.

There’s one important difference between AC MCB and DC MCB. While both have a similar purpose, the AC MCB trips more easily. In fact, AC MCBs are typically more durable and last longer than their DC counterparts. 

While the two types of MCB have the same purpose, the main difference between them is their voltages. AC MCBs protect against high-frequency surges, while DC ones protect against short-circuit problems. AC MCBs use alternating current, while DC MCBs use direct current. 

If you want to know more about the difference between AC MCB and DC MCB, continue reading this article. 

What Is an AC MCB?

MCB is a type of electrical switch that protects your home and your property from damage caused by electrical surges. There are two types of MCBs: type A and type B. Type A is used for residential and light commercial applications, while type B is used in industrial settings, such as winding motors.

AC circuit breakers work on the basis of the alternating current (AC). The voltage varies from -V to +V 60 times per second. Whenever a 0v point is reached, the MCB will interrupt the circuit. It will extinguish any arc that results from too much current. 

It will protect wiring from damage caused by excessive current and protect your electrical equipment. AC miniature circuit breakers come in a variety of types. It is important to choose the right one for your needs and the place where it will be used.

What Is DC MCB?

DC MCB is used in the electrical system of automobiles. These are battery-powered circuits that convert solar radiation into direct current, which is used for electronics. To protect such devices, you need a DC MCB. An electric inverter is also required to convert DC power to AC power.

In some applications, an MCB is used to protect against overcurrent and circuit shorts. It protects against these conditions by interrupting the flow of power within a short time. To be effective, it must be able to interrupt a fault current below its rated short-circuit current. The best way to identify which circuit breaker you need is to determine its voltage rating. It is best to choose one with the same rating as the circuit.

Another type of MCB is a non-polar DC one. This type is labeled with a “+” and a “-.” The polarity of a DC MCB is determined by its markings. A DC MCB can either protect a single DC load or the main circuit. A DC MCB is more complicated to disconnect than an AC MCB.


If you’re considering purchasing an MCB for your electrical circuits, you need to know the difference between an AC and a DC model. You can use the MCB size table below to determine the properly sized device. AC MCBs are generally less expensive and are more commonly used in home electrical systems. DC MCBs, on the other hand, are significantly more expensive.

One difference between an AC MCB and a DC MCB is the arc interrupting capacity. AC MCBs must have a rated capacity for the voltage of the circuit they are connected to. This rating is based on the utility’s available current during a short circuit condition. The DC MCB, on the other hand, is not affected by the impedance of the circuit and is, therefore, more likely to open.

Another difference between AC and DC MCBs is the polarity. Non-polar DC MCBs are non-polar. Their labeling is non-directional and is, therefore, more useful in systems that have batteries for energy storage. This type of MCB provides protection against excessive currents and can protect circuits using energy storage batteries. An incorrectly wired AC MCB may not provide adequate protection.

The main difference between AC and DC MBs is their usage. AC MCBs protect main circuits while DC MBs protect individual load circuits. While AC MCBs are typically more efficient, DC MBs are often more difficult to reset because DC voltage is constant and harder to disconnect than AC. Depending on the type of system you have, you may want to purchase an AC-compatible DC MCB.

AC MCBs are generally smaller and lighter than their DC counterparts. Compared to AC MCBs, DC MBs are smaller and more durable. As such, they can be replaced with an isolator and fuse when the circuit is overloaded. Besides being smaller, these breakers are also easier to install. You may also need an extra outlet for each circuit. If you’re worried about wire size, you can use a fuse for the AC MCB.

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