The MCB will not stay on
Usually a worn-out mechanism, especially on MCBs that are 10+ years old or have tripped many times. We test, confirm it is the breaker and not the wiring, and replace.
24/7 emergency electrician in SingaporeBCA Registered | EMA Licensed | LEW Certified
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- Electrical Repair
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Same-day diagnosis
Circuit Breaker Replacement & Repair Singapore MCB & RCBO, Most Jobs Done in One Visit
Something in your DB box keeps tripping, or a switch just will not stay up? TRUST ELECTRICIANS handles circuit breaker replacement and repair across Singapore for HDB, condo, landed and commercial properties. We carry the common sizes in our van, so most jobs are finished in a single visit.
We test before we replaceGet a free quote
Breakers on the vanSchneider, ABB, Hager, Legrand, Clipsal
- 20–40 min per breakerFor a simple like-for-like swap
- Tested, not guessedMultifunction tester, every time
- BCA registered, LEW-certifiedEMA-compliant, to CP5
- HDB, condo, landed & commercialLicensed & insured local team
Registrations & certifications you can checkSingapore-registered and EMA-licensed
Breaker or wiring?
Faulty Circuit Breaker Symptoms (How to Tell)
A faulty breaker and a real wiring fault look very similar from the outside. That is why we always test before we replace. Common signs the breaker itself is the problem:
- Loose or floppy when you toggle itThe internal mechanism has worn out.
- Trips with everything unpluggedNo load and it still trips: the breaker is the most likely culprit.
- Trips only when you switch it onNot under load. Another sign of mechanism failure.
- Warm to the touchIt never should be. Warmth means a poor internal connection.
- Buzzing or hummingUsually a failing contact. Treat it as urgent.
- Discoloured, cracked or melted handleHeat damage has already started. Replace immediately.
Recent Circuit Breaker Jobs Across Singapore
Worn MCBs, failed RCCBs, burnt boards and breakers sized wrong for the cable behind them. Every one tested before and after replacement by our own electricians.
DB box breakers replacedNeat, colour-coded MCBs 
New breakers, rewired DBEvery circuit labelled and tested 
MCB & RCCB board fittedSingapore HDB flat 
Worn RCCB replaced63A 30mA device, same visit 
Tripping breaker diagnosedTested before replacing 
Burnt distribution boardFailed breakers found and replaced 
Overloaded circuit foundBreaker resized to suit the cable 
Power restored safelyNew breakers tested under load 
Old fuse box, before upgradeReplaced with a breaker DB 
RCCB tripping on leakageCircuit isolated and tested 
Commercial DB & panel worksBreakers for a business 
Industrial control panelDistribution board rewiring
Not sure which breaker you have? Send a photo of the open DB box and we will bring the right replacement.
WhatsApp Your DB PhotoWhat we do most days
Circuit Breaker Replacement
You have a breaker that is failing, and we swap it for a new one. These are the jobs we see most often in Singapore homes and businesses.
Visibly damaged MCB
Discoloured, melted, cracked or smelling burnt. This one is urgent. We isolate the circuit, replace the breaker and check the cable behind it for heat damage.
Adding a new circuit
New aircon, water heater or socket run with no spare ways? We add a new MCB, run the cable and label the circuit. DB-side work is on our DB Box Electrician Singapore page.
Upgrading MCB to RCBO
For better personal protection on a socket or water-heater circuit, we fit the RCBO in the same slot and verify discrimination with the main RCCB.
Like-for-like during a renovation
If your ID is opening up the walls anyway, it is a good time to refresh the breakers at the same time.
How long it takes
20–40 minutes per breaker for a simple swap. A whole-DB re-look (every MCB replaced) is 3–5 hours.
- Schneider
- ABB
- Hager
- Legrand
- Clipsal
Over 2,500 Electrical Jobs Completed Across Singapore
From a breaker that would not stay up to a full DB of new MCBs, here is what Singapore homeowners and businesses say about us on Google.
In plain English
What Is a Circuit Breaker? MCB vs RCBO
A circuit breaker is the small switch inside your DB box that protects one circuit. When that circuit is overloaded, shorted or drawing too much current, the breaker trips and cuts the power. It is doing its job. There are two main types in a Singapore DB box:
MCB (Miniature Circuit Breaker)
Protects against overload and short circuit. This is the standard breaker for lighting, sockets, aircon and water heater: every circuit in your home.
RCBO (Residual Current Breaker with Overcurrent)
Does everything an MCB does, plus detects earth leakage, the dangerous kind where current leaks to ground through a person or water. It is an MCB and an RCCB combined into one device.
For dedicated safety switches that protect whole groups of circuits, see our ELCB / RCCB Installation Singapore page.
Circuit Breaker Sizing (Amps, Type B/C/D)
Picking the wrong breaker is a real safety risk: too small and it trips under normal load, too large and it does not protect the cable behind it.
- BType BTrips at 3–5 × rated current. For general residential loads.
- CType CTrips at 5–10 × rated current. For higher inrush: motors, transformers, some aircons.
- DType DTrips at 10–20 × rated current. Very high inrush loads; rare in homes.
If your aircon trips a Type B breaker at start-up but is fine after, the fix is usually a Type C of the same rating, not a bigger breaker. We always check this on site.
Typical Singapore residential circuits
CircuitTypical breaker sizeBreaker type
Lighting (general)6A or 10AType B or C
General 13A sockets16A or 20AType B or C
Kitchen / dedicated appliance20AType B or C
Window / wall aircon (small)16A or 20AType C
Aircon (multi-split, larger)25A or 32AType C
Instant water heater20A or 32AType C
Electric oven / induction32A or 40AType C
Main switch (whole house)40A, 60A, 80A, 100ANot applicable
For commercial main breakers, sizing and discrimination rules are more involved. See Commercial Electrician Singapore.
Breaker Warm, Buzzing or Will Not Stay On?
Do not risk a guess. A wrong-sized or unbranded breaker is a real fire hazard. Switch that circuit off and call us; we test first and replace on the spot when it really is the breaker.
Pricing
Circuit Breaker Cost in Singapore
The breaker itself is cheap, and so is the labour to fit it. The deciding factor in total cost is whether the swap is the whole job, or whether we also need to find out why it failed.
We always give you a written fixed quote before any work begins. If we find something on site that genuinely affects safety, we pause, explain it and quote separately before continuing. Full current rates are on our Electrical Services Price List Singapore.
$15–$60The breaker itselfBy brand, rating, MCB or RCBO
< 30 minSingle MCB swapLike-for-like, same visit
A few hoursNew MCB + new circuitNeeds DB capacity and cable
3–5 hrsWhole-DB re-lookUsually bundled with a DB upgrade
How we work
Our Circuit Breaker Service Process
A photo first, a proper test on site, and a replacement only when the breaker really is the fault.
20–40 minPer breakerSimple swap
1 visitMost jobsParts on the van
- WhatsApp us a photo of the open DB box. We identify the brand, model and rating you have, bring the right replacement and give you an indicative quote in advance.
- Phone triage. Which circuit trips, what happens when you reset, any burning smell, anything visibly damaged. It helps us confirm it is the breaker before we come.
- Site visit. We arrive on time, isolate the affected circuit and test the breaker with a proper multifunction installation tester, not just a visual check.
- Confirm the diagnosis. If it really is the breaker, we replace it on the spot. If the breaker tests fine and the fault is the wiring or an appliance, we tell you and quote accordingly.
- Test under load. Every new breaker is tested under realistic load before we leave.
- EMA-compliant, LEW-supported. Every replacement is to Singapore Standard CP5; for new circuits or DB changes we issue a LEW-signed Certificate of Compliance.
We test before we replaceYou will not pay for a breaker you did not need.
Why Homeowners Trust Us for Circuit Breaker Work
- Licensed & LEW-endorsedEvery meaningful job is signed off by a Licensed Electrical Worker registered with the EMA.
- We test before we replaceYou will not pay for a breaker you did not need.
- EMA-approved components onlySchneider, ABB, Hager, Legrand, Clipsal or equivalent. No unbranded substitutes.
- Same-day or next-day slotsFor most breaker jobs.
- Clean, polite, on timeDrop sheets, shoe covers and a tidy site are the default.
- Fixed, written quotesThe price we quote is the price you pay.
Areas We Cover for Circuit Breaker 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
Circuit Breaker FAQs
Straight answers about faulty breakers, MCB vs RCBO, DIY and lifespan.
How do I know if my circuit breaker is faulty or if it is the wiring?
The short version: if the breaker trips even when nothing is plugged in and no lights are on, the breaker is the more likely culprit. If it trips under load, it could be either, and you need a test. We test every breaker before we replace it.
Can I replace a circuit breaker myself?
No. Circuit breaker 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, even with the main switch off. A mistake here is not a small mistake.
What is the difference between an MCB and an RCBO?
An MCB protects the cable from overload and short circuit. An RCBO does that, plus protects people from earth leakage. RCBOs cost more, but for socket and water-heater circuits in HDB and condo, the personal safety benefit is significant. See our ELCB / RCCB Installation Singapore page.
My MCB trips only at night. What could it be?
Usually one of three things: an appliance on a timer (water heater, aircon, dryer), an overloaded circuit at peak evening load, or a genuine intermittent fault that warms up under use. Send us a WhatsApp describing the pattern and we will tell you which one it most likely is.
How long does a circuit breaker last?
A good-quality MCB (Schneider, ABB, Hager) is rated for around 10,000 mechanical operations and several thousand trips. In a typical home that is 15–25 years. Cheaper unbranded MCBs fail sooner. We recommend replacing breakers that are 15+ years old as part of any DB upgrade.
Need a Circuit Breaker Replaced Right Now?
MCB will not stay on, is warm, buzzing, cracked or tripping without load? Or adding a new aircon, water heater or socket circuit? TRUST ELECTRICIANS Singapore provides fast, safe and properly sized circuit breaker replacement and installation.
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