ELCB
Earth Leakage Circuit Breaker. Still widely used in Singapore. Functionally equivalent to a modern RCCB.
24/7 emergency electrician in SingaporeBCA Registered | EMA Licensed | LEW Certified
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ELCB / RCCB Installation & Replacement Singapore Shock Protection & HDB 2nd RCCB Compliance
ELCB and RCCB are the safety switches in your DB box that protect your family from electric shock, cutting the power in milliseconds when current leaks to ground. TRUST ELECTRICIANS installs, replaces and tests them for HDB flats, condos and landed houses, with the right sensitivity for every circuit.
Licensed & insured, LEW-supervisedHDB 2nd RCCB requirement
Right sensitivity30mA or 100mA, matched to the circuit
- 30mA personal protectionTrips in under 30 milliseconds
- 2nd RCCB in 1–2 hoursWith a small LEW-signed CoC
- Branded devices onlySchneider, ABB, Hager, Legrand
- HDB, condo & landedBCA registered, EMA-compliant
Registrations & certifications you can checkSingapore-registered and EMA-licensed
HDB compliance
HDB 2nd Circuit Breaker / RCCB Requirement
This is a big one, and it catches a lot of HDB homeowners off guard.
The ruleSince 2024, HDB requires the socket circuit and the water-heater circuit in an HDB flat to be protected by a dedicated RCCB (or RCBO) of 30mA sensitivity, in addition to the main RCCB. It is often called the "HDB 2nd circuit breaker" or "HDB 2nd RCCB" requirement.
Why it matters
- The main RCCB protects the whole house. If it trips, everything goes dark and you cannot easily tell which circuit caused the fault.
- The 2nd RCCB isolates the fault to the socket or water-heater circuit, so only those circuits lose power and the issue is quick to find.
- It is required for HDB resale handovers, certain renovation works and any new HDB electrical installation.
What it means in practice
- If your flat was built or last rewired before the rule came in, you probably do not have one. We can add it as a standalone visit.
- If you are renovating, your ID should specify the 2nd RCCB in the electrical drawing. We install it as part of the rewiring.
- If you are selling or sub-selling, the buyer's bank and HDB may ask for evidence of compliance.
See also DB Box Electrician Singapore for the DB side, and Water Heater Installation & Replacement for the water-heater side of the same story.
Recent ELCB & RCCB Jobs Across Singapore
Failed RCCBs replaced, leaks traced before anything was swapped, and 2nd RCCBs added for HDB compliance. Every device tested at its rated sensitivity by our own electricians.
Worn RCCB replaced63A 30mA device, same visit 
RCCB tripping on earth leakageLeak traced before replacing 
MCB & RCCB board fittedSingapore HDB flat 
DB rewired with RCCB protectionEvery circuit tested at 30mA 
Protection devices upgradedNeat, colour-coded DB 
New DB with main RCCBHDB and condo installation 
Water heater circuit protectedDedicated 30mA protection 
Storage water heater, HDBWired to a protected circuit 
Certified safety-switch wiringLEW inspection and CoC 
RCCB fault diagnosedTested with a multifunction tester 
Power restored safelyReset only after the leak was fixed 
Overloaded DB checkedProtection re-balanced
Not sure what is in your DB? Send a photo of the open DB box and we will tell you within minutes.
WhatsApp Your DB PhotoClear breakdown
ELCB vs RCCB vs RCBO: Which Do You Need?
These three terms get used interchangeably in Singapore, and it confuses everyone. Same idea, different names and features.
RCCB
Residual Current Circuit Breaker. The modern, technically correct name. Pure earth-leakage protection with no overcurrent protection, so it is always paired with an MCB.
RCBO
Residual Current Breaker with Overcurrent protection. RCCB + MCB in one device: earth-leakage and overload protection in a single DB slot.
So which do you need?
- Most HDB socket and water-heater circuits: ideally a 30mA RCBO. Many older HDB installations use a 30mA RCCB + MCB combo, which is also fine, just bigger.
- Whole-house protection at the main switch: typically a 30mA or 100mA RCCB, depending on the installation.
- Sub-distribution (a sub-DB feeding a sub-area): often a 100mA RCCB for fire protection.
- Lighting-only circuits generally do not need individual RCCB protection; the main RCCB covers them.
Over 2,500 Electrical Jobs Completed Across Singapore
From an RCCB that tripped every time it rained to a 2nd RCCB added before an HDB resale, here is what Singapore homeowners say about us on Google.
In plain English
What Is an ELCB / RCCB? Earth Leakage Protection
Imagine standing on a wet floor and touching a kettle with a damaged cord. Current flows from the live wire, through the kettle, through you, into the floor. A regular circuit breaker will not necessarily save you: the current may be too low to trip it, but more than enough to kill.
An ELCB / RCCB notices this. It constantly compares the current going out on the live wire with the current coming back on the neutral. If it detects even a tiny imbalance (typically 30 milliamps), it trips in under 30 milliseconds, fast enough to prevent serious injury or death.
30mAPersonal protectionSockets, water heaters, the HDB 2nd RCCB
100mAFire & equipmentMain switch or sub-DB
300mAFire protection onlyCommercial or industrial; rare in homes
25A–100ACurrent ratingMatched to the circuit or main incoming
RCCB rating for home: getting it right
The wrong sensitivity either does not protect you, or trips constantly. The current rating (25A, 40A, 63A, 80A, 100A) is the maximum current the device can carry; the overcurrent job is still done by the MCB, but the RCCB itself has a limit, matched to the circuit or the main incoming supply.
Safety Switch Will Not Trip When You Press Test?
A failed safety switch means your family is not protected from electric shock. Call us for a same-day or next-day replacement, tested at its rated sensitivity before we leave.
Check yours
Signs Your ELCB / RCCB Is Faulty
A safety switch that does not work is worse than none, because you think you are protected when you are not. The good news: the test is a single button.
- Test button does nothingPress "T" monthly. If it does not trip immediately, the device has failed: replace it.
- Will not stay on after a tripUsually the leakage fault is still present. We find the leak rather than replace a working RCCB.
- Random trips, no obvious causeA degrading RCCB, or a real intermittent leak (water ingress, damp wall, failing appliance). We test both.
- Warm to the touchIt never should be. A warm RCCB means a poor internal connection. Treat it as urgent.
- Loose, discoloured or cracked handleReplace it. Do not wait.
How we work
Our ELCB / RCCB Service Process
We test the device and the circuit first, so you never pay for an RCCB you did not need.
1–2 hrs2nd RCCB installIncluding the CoC
On the spotLike-for-like swapDevice on the van
- Photo of the open DB box. WhatsApp a clear photo showing the existing RCCBs and RCBOs. We identify the brand, rating and slot availability before we arrive.
- Phone triage. Which circuit is affected, does the test button work, when did it start. It helps us bring the right device.
- Site visit. We test the existing RCCB with a multifunction tester, confirm whether the device or the circuit is at fault, and quote accordingly.
- Replacement or addition. Like-for-like swaps are done on the spot. For a new 2nd RCCB, we fit the device, re-wire the relevant circuits, label clearly and test.
- Test under realistic conditions. Every new RCCB / RCBO is tested at its rated sensitivity, and we show you the monthly test button routine.
- LEW sign-off and CoC. Any new RCCB / RCBO addition needs a LEW endorsement and CoC. We issue it in the same visit.
HDB 2nd RCCB specialistsThe right device and the LEW paperwork, done right.
Why Homeowners Trust Us for ELCB / RCCB Work
- Licensed & LEW-endorsedEvery meaningful job is signed off by a Licensed Electrical Worker registered with the EMA.
- EMA-approved devices onlySchneider, ABB, Hager, Legrand or equivalent. No unbranded substitutes.
- HDB 2nd RCCB compliance specialistsWe know the HDB rule, the right device (40A 30mA RCBO) and the LEW paperwork required.
- Test before we replaceWe will not sell you an RCCB you do not need.
- Clean, polite, on timeDrop sheets, shoe covers and a tidy site are the default.
- Same-day or next-day slotsFor most RCCB jobs.
Areas We Cover for ELCB / RCCB Work
Islandwide Singapore, no travel surcharge. For landed properties and private estates, we have the same islandwide footprint and response times.
We regularly attend electrical repair calls in
- Tampines
- Bedok
- Sengkang
- Punggol
- Yishun
- Woodlands
- Jurong West
- Jurong East
- Bukit Batok
- Toa Payoh
- Ang Mo Kio
- Hougang
- Serangoon
- Bishan
- Clementi
- Queenstown
- Choa Chu Kang
- Bukit Panjang
- Pasir Ris
- Kallang
- Geylang
- Marine Parade
- Bukit Merah
- Bukit Timah
- Holland Village
- East Coast
ELCB & RCCB FAQs
Straight answers about ELCB vs RCCB, the HDB 2nd RCCB, testing and tripping.
What is the difference between an ELCB and an RCCB?
Functionally, almost nothing in a Singapore home. Both are earth-leakage safety switches that trip on residual current. "ELCB" is the older name still widely used; "RCCB" is the modern, technically correct term. The device in your DB is most likely an RCCB, even if you call it an ELCB. The newer combined device is the RCBO (RCCB + MCB in one).
Do I need a 2nd RCCB for HDB?
Since the 2024 HDB requirement, yes, for the socket and water-heater circuits. A 30mA 40A RCBO on those circuits isolates faults faster, makes diagnosis easier, and is required for HDB resale handovers and most renovation sign-offs. If your flat does not have one, we can add it as a standalone job.
How often should I test my RCCB?
Monthly. Press the "T" or "Test" button. It should trip immediately. If it does not, replace the device: it has failed and you are not protected.
Can I replace an RCCB myself?
No. RCCB replacement is fixed-wiring electrical work under Singapore law, and must be done by or under the supervision of a Licensed Electrical Worker. The DB busbar is always live. A mistake here is dangerous, and the work will not be CoC-signed.
My RCCB keeps tripping. Is the device faulty or is there a real leak?
It depends. If it trips with nothing plugged in, it could be either. If it trips only when a specific appliance is on, that appliance is the most likely culprit. We test both the device and the circuit before replacing anything. Often the answer is a power trip issue or moisture ingress, and we handle that too.
Need an ELCB or RCCB Replaced, Added or Tested?
Safety switch will not trip on test, will not stay on after a trip, or you need the HDB 2nd RCCB? Do not wait. TRUST ELECTRICIANS Singapore provides fast, safe and HDB-compliant ELCB / RCCB installation and replacement.
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