MCB vs RCCB: Which is Best for Your Home Appliances?

Both MCB and RCCB devices are circuit breakers that protect against the risk of electrical overload. But between MCB and RCCB which one is the best to use in a home? To help you with that Lauritz Knudsen (Formerly L&T Switchgear) comes with a wide range of electrical protection devices including MCB and RCCB. 

Being one of the leading manufacturers of electrical equipment, including solar energy solutions, and voltage switchboards, Lauritz Knudsen (Formerly L&T Switchgear) brings you a user-friendly e-shop that provides a seamless experience. From electrical products, services and solutions for regulation, and monitoring to control of electrical wiring and installations, you find everything under one roof in the Lauritz Knudsen (Formerly L&T Switchgear). 

What is an MCB?

What is a MCB in electrical and how does it help are common questions when people are in need of it. Also known as a miniature circuit breaker MCB is an electronic device that is widely used in household and commercial wiring. This circuit breaker or interrupter helps avoid harm to the remainder of your electrical system, usually when an excessive current arises due to a short circuit. MSBs are one of the most basic circuit breakers that work on a straightforward concept known as overload protection. 

What is a RCCB?

RCCB is a residual current protection device that monitors the electrical current in the main and neutral lines of housing and commercial buildings. In full form, it is called a residual current circuit breaker. The primary function of the RCCB is to prevent electrical shocks and probable fire caused by poor electrical wiring. 

Differences Between MCB and RCCB 

The differences between MCB and RCCB are explained in the table below. 

Types of MCB and RCCB

MCBs and RCCBs are classified according to the tripping and number of poles. 

Based on the tripping nature, there are five types of MCB:

Type B MCB

The type B MCB trips at 3 to 5 times full load current. This type of MCB is mostly used in residential applications and light commercial applications where connected loads include lighting fixtures and household appliances with resistive components.

Type C MCB

Used in industrial or commercial types of applications, type C MCB trips between 5 and 10 times full load current. Where there is a possibility of increased short-circuit currents, this type of MCB is used. 

Type D MCB

Type D MCB trips at full load current 10 to 20 times. These MCBs are utilised in specialised industrial/commercial applications where the current inrush is quite high. Examples include massive winding motors, transformers X-ray equipment and so forth.

Type K MCB

This MCB trip at 8 to 12 times full load current. These are appropriate for inductive and motor loads requiring strong inrush current. Both K and D circuit breakers are used for motor applications where ampacity increases rapidly and briefly during "start-up." 

Type Z MCB

The Z MCB trips at 2 to 3 times the full load current. These MCBs are particularly sensitive to short circuits and are used to safeguard highly delicate electronics like semiconductors.

Based on the number of poles, there are five types of MCB:

Single-Pole MCB

A single-pole MCB switches and protects only one phase of a circuit.

Double-Pole MCB

As the name suggests, it offers switches and protects both the phase and the neutral. 

Triple-Pole MCB

A triple-pole MCB provides regulation and protects three phases and not the neutral. 

Three-pole with neutral

A three-pole with neutral MCB provides switching and protection to three phases as well as neutral, which is a distinct pole. However, the neutral pole has no protection and may merely be flipped.

Four-Pole MCB

Similar to the three-pole with neutral, four-pole MCB also has a safe release for the neutral pole. This MCB should be used when there is a risk of a large neutral current flowing through the circuit, such as in an unbalanced circuit.

There are 4 types of RCCB, depending on its tripping nature and two types depending on the number of poles: 

Type AC RCCB

It is a conventional type of RCCB and is built for use with sinusoidal AC circuits, as the name suggests. Thus, it cannot consistently identify DC defects, whether smooth or pulsed. The type A RCCB is appropriate for applications that do not contain electrical components that may generate DC faults: Use it just for the classic appliance.

Type A RCCB

It is an upgraded AC-type RCCB. It can detect both AC faults in sinusoidal circuits and pulsed DC faults. As such, it is compatible with many sorts of appliances, even those with electrical components.

Type F RCCB

The F-type RCCB can detect up to 1000Hz (1 kHz), making it ideal for use with variable frequency drives and other electrical devices. This type of RCCB is used to protect people from the fault currents generated by modern washing machines, fans and other equipment with a variable frequency motor or supply.

Type B RCCB

This RCCB has the capabilities of all the other types (A, AC and F). Plus, it has the capacity to measure and respond to smooth DC problems. As a result, it is the most adaptable form of RCCB, appropriate for use with any sort of powered equipment, including PV systems and wind turbines. 

Single-Pole RCCB

These RCCBs are designed for single-phase systems. They have one input (the live wire) and one output (the neutral wire). Because single-phase systems are often low voltage, the single pole or single-phase RCCB is most commonly employed in residential and small business settings. It is also often utilised in small and light enterprises.

Four-Pole RCCB

4-pole RCCB is intended for higher voltage three-phase circuits. It has three inputs (live wires) and one output (neutral). This sort of device is commonly used in industrial settings since it can tolerate higher current flows.

Uses of MCB and RCCB

MCB is an automatic switch that is designed to break current overload which may damage the electric circuit and lead to hazardous conditions. Meanwhile, uses of RCCB include sensing current and disengaging low voltage whenever a fault occurs which can electrocute a person and thereby kill him.

How are MCB and RCCB Connected?

To prevent electrical shocks and short circuits, MCB and RCCB are wired together in a specified sequence. All phase and neutral wires from your electrical source should go via your MCB first, then your RCCB. This ensures that your MCB can detect any short circuits or overloads in your lines or the lines connecting the MCB and the RCCB.

MCB and RCCB from Lauritz Knudsen (Formerly L&T Switchgear)

At Lauritz Knudsen (Formerly L&T Switchgear), you can avail of a myriad of electrical devices including protection devices like MCB and RCCB. You will get these under the final distribution products page. Our in-house design and development roots for modern and trusted electrical devices ensure smart protection against any electrical failure. Shop as a homeowner, builder or retailer, our SMARTSHOP is accommodating for all.