RCCB (Residual Current Circuit Breakers) in Singapore
Residual Current Circuit Breakers (RCCB) are mandatory safety devices that immediately terminate the electricity supply when it detects a leakage of current above accepted levels. These circuit breakers monitor electrical current and find imbalances between incoming and outgoing current, which are factors used to determine the presence of current leakage.
Current leakage occurs when electricity escapes from its intended path in a circuit, often due to factors like degraded insulation, malfunctioning appliances, presence of moisture, or improper wiring. This can lead to electric shocks or fires, making protective devices like RCCBs and ELCBs important, as they detect these leakages and promptly disconnect the power to prevent potential harm.
RCCBs have been mandatory in all residential properties constructed since July 1985. Additionally, every home that carried out renovations or electrical rewiring after this date and did not already have an RCCB installed had to include its installation as part of the renovation process.
Are RCCBs installed in all residential properties?
No, data from the Housing Development Board (HDB) indicates that about 1.3% of one-room and two-room flats completed in and before 1985 still do not have an RCCB installed as of May 2023.
Additionally, about 2% of three-room and larger flats from the same period still do not have it or have an RCCB installed that does not provide complete protection to the whole property.
It is not clear how many private residential or commercial properties do not have an RCCB installed at this time.
RCCB circuit breaker mandate
On May 12, 2023, the Energy Market Authority (EMA) informed the public and Licensed Electrical Workers (LEW) through a media release that all domestic electrical installations will be mandated to include at least one 30mA sensitivity RCCB.
This mandate came into effect on July 1, 2023, and seeks to bolster electrical safety across all Singaporean households, ensuring protection from electric shock. Homeowners have been provided a grace period lasting till July 1, 2025 to comply with this mandate. After the grace period ends, the EMA or its appointed agents will conduct random enforcement checks focused on pre-1985 HDB flats and private homes.
What if you have an ELCB
EMA has confirmed that if you have an Earth Leakage Circuit Breaker (ELCB) installed in your home, you do not need to change it to an RCCB. Even though the two circuit breakers operate in different manners, they are both electrical safety devices that immediately terminate the electricity supply when a leakage is detected. We have written an article breaking down the differences between ELCBs and RCCBs.
What happens if you do not comply
Residences found without an RCCB will first be issued a written warning and given an additional eight-week grace period to install an RCCB. In cases of continued non-compliance, homeowners might face stiff penalties, with fines escalating to as much as S$5,000 on conviction under Provision 40(1) of the Electricity (Electrical Installations) Regulations.
Homes that are found to be equipped with malfunctioning RCCBs will not be fined, but will be strongly encouraged to engage an electrician services company to carry out repair and replacements where necessary to maintain a high standard of electrical safety within their homes.
RCCB safety was already a component of the HDB Home Improvement Programme
For Home Improvement Programmes (HIP) tendered by the Housing & Development Board (HDB) in 2020 and onward, a provision has been included for the checking and replacement of faulty Residual Current Circuit Breakers (RCCBs).
This initiative was part of HDB's broader objective to enhance electrical safety in residential flats under its Home Improvement Programme (HIP). The systematic inspection and replacement of faulty RCCBs aimed to ensure the safe operation of electrical systems within HDB flats, which aligns with the new electrical safety standards that have become mandated in July 2023.
Additional note: In August 2020, the HIP was further expanded to include an option for the rewiring of non-compliant water heaters in flats undergoing the programme. This measure sought to address potential electrical hazards associated with water heating systems, contributing to the overall electrical safety within HDB flats.
What if you are not sure if you have an RCCB installed
The RCCB has a round or rectangular button, and should be the second circuit breaker from the left or right within the distribution board (also referred to as the DB box or circuit breaker box). Those residing in HDB flats who are struggling to locate the RCCB can reach out to the Branch Service Line at 1800-225-5432 for assistance, and those residing in private properties should reach out to an electrician for assistance.
How Does an RCCB Work?
RCCBs are devices that can detect minor variations in residual current by continuously monitoring and comparing the current values between the live and neutral wires of the circuit they are safeguarding. They operate based on Kirchhoff's Current Law (KCL), an electrical principle which states that the total current entering a circuit should equal the total current exiting it. The difference in the current values between live and neutral wires is called residual current.
RCCBs ensure that any residual current remains within permissible tolerance levels, which in most cases is set at 30mA. When the residual current levels exceed the allowed tolerance levels, it immediately disconnects the electrical supply.
Why is RCCB sensitivity set at 30mA
The human body can endure an electric shock up to a certain extent, and the impact of the shock is based on the level of current. A 5 mA current can deliver a slight shock, and at a range of 6 mA to 16 mA, the shock can become painful, potentially causing a loss of muscular control. As the current further increases, it can cause extreme pain and severe muscular contractions. At 30 mA, the shock can cause respiratory paralysis, a condition which results in the inability to breathe due to the failure of the respiratory muscles.
How to check if your RCCB is working
Ensuring the RCCB is in optimal working condition is paramount for household safety. Periodic testing can help identify any malfunctions before they culminate in major issues. Here’s how to test your RCCB:
- Preparation: Prior to testing, it’s imperative to switch off all appliances. This prevents potential damages during the test.
- Initiate the Test: Every RCCB is equipped with a test button. Pressing this should cause the RCCB to trip, signifying its correct functionality. If it successfully disconnects the power supply, it is functioning as expected.
- Inspect Lights and Sockets: While the RCCB is tripped, ensure no power reaches any lights or sockets. If any appliance or light remains operational despite the tripped RCCB, it's indicative of a malfunction, signalling that the RCCB isn't providing the intended protection.
- Restoring Power: After testing, all electrical points should be switched off. Subsequently, reset the RCCB to its original position to restore the power supply.
What is the financial burden of RCCB installation?
For one-room and two-room HDB flats, the cost for installation and necessary rewiring is entirely shouldered by the government. HDB has already assisted these lower-income households with their RCCB installations.
For homeowners of three-room and larger flats completed in and before 1985 without an RCCB, read the next section for information about the Installation Assistance Programme. Under this initiative, the government will subsidize up to 87.5% to 95% of the installation cost and required rewiring jobs.
Private homeowners are expected to ensure a working RCCB in their homes at their own cost. They must employ an electrician to perform the installation, and should expect to pay an electrician between $500.00 to $1,000.00. The cost of this procedure will be borne entirely by the private homeowner.
Installation assistance programme
The Installation Assistance Programme for Residual Current Circuit Breakers (RCCBs) is a scheme initiated by the Housing & Development Board (HDB) of Singapore to reduce the financial burden complying to this mandate has on residents. The actual amount residents need to pay can range between 5% to 12.5% of the total installation cost, depending on the type of flat they occupy.
The programme is eligble to Singaporean homeowners with HDB flats that were completed on or before 1985 and that have not had an RCCB installed. Under this initiative, HDB will subsidise the cost of installing an RCCB based on the flat type, in accordance with the table below.
| Flat Type | 3-Room | 4-Room | 5-Room | Executive |
|---|---|---|---|---|
| Percentage of the cost to be paid by flat owners | 5% | 7.5% | 10% | 12.5% |
| Estimated amount payable by flat owners | $25.00 | $37.50 | $50.00 | $62.50 |
Eligible homeowners may apply for the Installation Assistance Programme for Residual Current Circuit Breakers through HDB's feedback form.
This initiative not only seeks to improve the electrical safety standards in older HDB flats but also aims at making it financially feasible for the residents, including those from lower-income and more vulnerable households, to upgrade their electrical infrastructure to modern safety standards.
The programme forms part of a broader commitment by the Singapore Government and HDB to enhance living conditions in public housing, ensuring that they remain safe, comfortable, and up-to-date with essential safety standards.
