Please enter keywords to search

Global |EN

Choose your country & Language

Asia Pacific

Australia & New Zealand
India
Indonesia
Korea
Malaysia
Philippines
Singapore
Singapore (Sunlight)
Vietnam

Middle East & Africa

CHINT-EGEMAC
Saudi Arabia
South Africa
UAE
CHINT AJLAN
Egypt
Kenya

Europe

France
Kazakhstan
Netherlands
Italy
Spain
Turkey
United Kingdom

North America

Mexico

Latin America

Brazil
Colombia
Ecuador
Peru

Choose your country & Language

Australia & New Zealand
India
Indonesia
Korea
Malaysia
Philippines
Singapore
Singapore (Sunlight)
Vietnam
CHINT-EGEMAC
Saudi Arabia
South Africa
UAE
CHINT AJLAN
Egypt
Kenya
France
Kazakhstan
Netherlands
Italy
Spain
Turkey
United Kingdom
Mexico
Brazil
Colombia
Ecuador
Peru

Please enter keywords to search

Your search term contains restricted words. Please use different keywords.

Residual Current Operated Circuit Breaker (RCBO): Function and Application

AUG 19, 2023

Residual Current Operated Circuit Breaker
Residual Current Operated Circuit Breaker
Residual-Current-Operated-Circuit-Breaker

Table of Contents

  1. What is a Residual Current Operated Circuit Breaker?
  2. The Functions and Mechanism of RCBOs
  3. RCBO Applications
  4. What Circuits Need RCBO Protection?
  5. Where are RCBOs Required?
  6. Conclusion

In today’s modern world, there’s no lack of sensitive electrical equipment that we rely on throughout our day-to-day life. With costly electrical investments, it’s important to always have a residual current-operated circuit breaker (RCBO) for an added layer of protection.

What is a Residual Current Operated Circuit Breaker?

Residual current operated circuit breakers are devices that protect specific electrical circuits from overloading or short circuits that could lead to system damage or human harm. Essentially, RCBOs combine the basics of a residual current device (RCD) with miniature circuit breakers (MCBs) to create a high-functioning protection device.

The main job of this electrical device is to detect when anything is awry with your electrical system and automatically disconnect the power going to it. RCBOs will detect earth leakage, short circuits, and even overloading. Unlike their RCD counterparts, the RCBOs are able to provide higher tripping currents to better protect more sensitive electrical equipment.

The Functions and Mechanism of RCBOs

RCBOs are specifically designed to provide the ultimate protection for appliances, people, and electrical circuits alike. Each residual current circuit breaker will continuously detect both the line current and earth leakage current of any device or circuit it’s connected to.

It will determine whether the line current is overpowered or when there is too much earth leakage from the current. These measurements are the key to providing a safe electrical setup in all residential, commercial, and industrial settings.

Whenever the RCBO detects that the leakage current is above the predetermined threshold, it will automatically disconnect the power. This will protect human operators from harmful electrical shocks.

RCBOs also function to disconnect power whenever an excessive current is detected. This works to protect appliances and electrical equipment from overloading and short circuits. It also protects from prospective fire hazards caused by excessive heat created by the extreme current.

RCBO Applications

Residual current operated breakers are ideal for circuits where overload and short circuit protection are necessary. This works in residential, commercial, and industrial settings. RCBOs are an ideal and typically cheaper option for applications where both MCBs and RCBs are required. Additionally, they save on installation time compared to installing both MCBs and RCBs onto a particular circuit.

RCBOs are a great choice for sensitive appliances, industrial equipment, and electrical circuits. These residual current operated circuit breakers can be specifically programmed to lower predetermined earth leakage current and line current detection thresholds. This is perfect for applications where you need to have a minimal threshold to protect the integrity of costly equipment and appliances.

Various types of RCBOs can be installed depending on your specific application requirements. Currently, five different types of these devices can be installed, including S, AC, A, F, and B. Type S is specifically designed to incorporate a time delay into the circuit. Type AC is the most common residual current circuit breaker installed in residential homes and has no time delay.

Type A is applied when dealing with residential pulsating DC current up to 6mA. Type F is ideal for frequency-controlled appliances like dishwashers, air conditioners, and washing machines. Lastly, Type B is used for both single and three-phase equipment, including welders, escalators, lifts, inverters, and photovoltaic systems.

What Circuits Need RCBO Protection?

There are numerous applications where RCBO protection is extremely useful to implement, such as with commercial or even residential solar installations. Due to the exact nature of these protection devices, they can be used in various situations where overloading and short circuits may pose a potential risk for people, appliances, and circuits.

Overloading, known commonly as overcurrent, can occur in various instances. For example, you may use a power strip to plug in too many electrical devices. With all of these devices drawing an excessive amount of power together, it can transfer more power than the cable’s threshold. 

This can lead to excessive overheating of the cable and a prospective fire. The presence of a residual operated circuit breaker will detect the excessive line current and disconnect the power before overheating and a fire happens.

Most short-circuiting will occur whenever there is earth or current leakage on a circuit. This happens when there’s an accidental breakage in the current. This breakage can occur for numerous reasons, including wiring errors or simple user mistakes like unintentionally cutting through a wire. 

If no residual current operated circuit breaker is installed, the current will continue to leak and cause physical harm to the human operator via dangerous electrical shock.

Where are RCBOs Required?

RCBOs are a great choice for applications where quick disconnect time is mandatory on a circuit or appliance. Residual current operated circuit breakers are programmed to disconnect power from the circuit or appliance whenever the line current exceeds the predetermined threshold. This is typically a mandatory requirement for both industrial and commercial settings.

Also, RCBOs are ideal for both commercial and industrial use where individual circuits need to be controlled independently from other circuits. Businesses need to maintain operations whenever one circuit becomes faulty due to overloading or short-circuiting.

RCBOs are the ideal option for controlling the outage to one specific circuit while leaving the remaining circuits still running independently and smoothly.

Conclusion

RCBOs are a great option for numerous residential, commercial, and industrial projects where overload and short circuit protection are vital. CHINT currently offers high-quality residual current operated circuit breakers that can be specifically tailored to meet the needs of your next electrical project.

FAQ about Residual Current Operated Circuit Breaker

Why is RCBO essential in electrical systems?

Can I replace a circuit breaker with an RCBO?

Is it expensive compared to traditional circuit breakers?

The Latest
DECEMBER 17, 2025 Understanding Power Losses: How Modern Switchgear Mitigates Inefficiency

Learn how power quality devices, LV switchgear, and shunt reactor solutions cut energy waste and improve electrical performance.

DECEMBER 15, 2025 Power Components for Solar and Storage Equipment

Discover the functions of the different specialized DC components and how these work together to protect, isolate, and measure solar and storage systems.

DECEMBER 12, 2025 Designing Turnkey Substations: From Specification to Commissioning

Learn how EPC teams use MV switchgear, HV switchgear, AIS, and HV MCCB to design efficient turnkey substations from spec to commissioning.

DECEMBER 10, 2025 Preventing Electrical Fires in Multi-Unit Buildings

Learn practical ways to improve electrical fire safety in multi-unit buildings with modern electrical safety devices and layered protection.

DECEMBER 8, 2025 Integrating Renewable Energy into Existing Grid Networks

Integrate renewables smoothly with modern power transformer solutions that stabilize voltage, support bidirectional flow, and strengthen grid reliability for clean energy growth.

DECEMBER 5, 2025 5 Ways to Cut Energy Costs in High-Load Industrial Environments

Energy efficiency is important in high-load industrial environments. Learn why knowing your power factor and reactive power compensation is important.

DECEMBER 5, 2025 Integrating VFDs to Optimize Motor Control in Heavy Industry

VFDs optimize your motor control, especially if you’re in a heavy industry setting. Learn how a variable frequency drive improves your process automation.

DECEMBER 5, 2025 Safe and Reliable Power Components for Smart HVAC Systems

Reliable electrical protection keeps HVAC systems safe, efficient and working smoothly. Explore how contactors, overload relays, and VFDs optimize performance.

DECEMBER 5, 2025 Choosing UL and IEC Components for Dual Market Equipment

Dual standards and dual certification are important in MCCBs. Learn how to choose UL and IEC components for dual market equipment to ensure safety.

DECEMBER 5, 2025 A Complete Guide to Selecting MCBs and RCCBs for Modern Buildings

Discover how to choose the right devices in the MCB vs RCCB lineup for safer, more reliable systems. Learn practical steps to strengthen electrical protection in modern buildings.