Circuit Breaker Replacement & Repair Singapore

Let me guess why you are here. Something in your DB box keeps tripping. Or you flipped a switch back up and it just will not stay. Or you opened the DB out of curiosity, saw something that did not look right, and started googling. Either way — you have landed in the right place.

A circuit breaker (or MCB — miniature circuit breaker) is one of those things you do not think about until it goes wrong. And when it does, it usually goes wrong at the worst possible time. Sunday night. Right before bed. With the water heater running and the aircon on full blast.

TRUST ELECTRICIANS handles circuit breaker replacement and repair across Singapore — HDB, condo, landed, commercial. We carry the common sizes in our van, so most jobs are done in a single visit. No “we’ll come back tomorrow” once we have quoted.

✅ BCA Registered ✅ LEW-Certified ✅ EMA-Compliant ✅ HDB / Condo / Landed / Commercial ✅ Same-Day Diagnosis ✅ Licensed & Insured Local Team

What Is a Circuit Breaker? (MCB vs RCBO, In Plain English)

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 for any reason, the breaker trips and cuts the power. That is the whole point of it. It is doing its job.

There are two main types you will see in a Singapore DB box:

MCB (Miniature Circuit Breaker) — protects against overload and short circuit. This is the standard breaker for lighting, sockets, aircon, water heater — every circuit in your home.
RCBO (Residual Current Breaker with Overcurrent protection) — does everything an MCB does, plus detects earth leakage (the dangerous kind, where current leaks to ground through a person or water). An RCBO is essentially an MCB and an RCCB combined into one device.

If you want a simpler mental model: an MCB protects the wire. An RCBO protects the person.

For the safety-switch side of things (pure earth leakage protection, no overcurrent), see our ELCB / RCCB Installation Singapore page. That page covers the dedicated safety switches used across whole groups of circuits.

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Circuit Breaker Replacement

This is what we do most days. You have a breaker that is failing, and we swap it for a new one. Common scenarios:

The MCB will not stay in the “on” position — usually a worn-out mechanism, especially on MCBs that are 10+ years old or that have tripped many times. We test, confirm it is the breaker and not the wiring, and replace.
The MCB is visibly damaged — discoloured, melted, cracked, or has a burning smell. This one is urgent. We isolate the circuit, replace the breaker, and check the cable behind it for heat damage.
You are adding a new circuit (new aircon, new water heater, new socket run) and there are no spare ways — we add a new MCB to the DB, run the cable, and label the new circuit. The full DB-side work is covered on our DB Box Electrician Singapore page.
You are upgrading from MCB to RCBO for better personal protection on a socket or water-heater circuit — we fit the RCBO in the same slot and verify the discrimination with the main RCCB.
Like-for-like replacement 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.

We carry common breaker sizes and brands on the van: Schneider, ABB, Hager, Legrand, Clipsal. If you need something specific, just let us know when you book.

Typical replacement time: 20–40 minutes per breaker for a simple swap. A whole-DB re-look (every MCB replaced) is 3–5 hours.

Faulty Circuit Breaker Symptoms (How to Tell)

The tricky thing about a faulty breaker is that the symptoms look very similar to a real wiring fault. A breaker that trips for no reason can look like a wiring fault, and a wiring fault can look like a faulty breaker. That is why we always test before we replace.

Common signs the breaker itself is the problem:

The breaker feels loose or floppy when you toggle it — the internal mechanism has worn out.
It trips even with everything unplugged on that circuit — if there is no load and it still trips, the breaker is the most likely culprit.
It trips only when you toggle it on, not under load — also a sign of internal mechanism failure.
It is warm to the touch — should never be. A warm breaker means a poor internal connection.
It makes a buzzing or humming sound — usually a failing contact. Treat as urgent.
The handle is discoloured, cracked, or melted — heat damage has already started. Replace immediately.

Common signs the wiring is the problem (not the breaker):

The breaker trips only when a specific appliance is turned on.
The breaker trips immediately every time you reset it, and nothing is plugged in.
The breaker is in good condition but the circuit still trips — this is what we cover on our Power Trip Electrician Singapore page.

When in doubt, send us a photo of the DB and a one-line description of what is happening. We can usually tell you which one it is within a few minutes.

Circuit Breaker Sizing (Amps, Type B/C/D)

Not all breakers are the same. Picking the wrong one is a real safety risk — too small and it trips under normal load, too large and it does not protect the cable behind it.

For typical Singapore residential circuits:

Circuit	Typical Breaker Size	Breaker Type
Lighting (general)	6A or 10A	Type B or C
General 13A sockets	16A or 20A	Type B or C
Kitchen / dedicated appliance	20A	Type B or C
Window / wall aircon (small)	16A or 20A	Type C
Aircon (multi-split, larger)	25A or 32A	Type C
Instant water heater	20A or 32A	Type C
Electric oven / induction	32A or 40A	Type C
Main switch (whole house)	40A, 60A, 80A, 100A	—

Type B trips at 3–5 × rated current — for一 residential loads.
Type C trips at 5–10 × rated current — for loads with higher inrush (motors, transformers, some aircons).
Type D trips at 10–20 × rated current — for very high inrush loads (large motors, welding). Rare in residential.

The “Type” matters. If your aircon is tripping a Type B breaker at start-up but is fine after, the fix is usually to swap to a Type C of the same rating — not to oversize the breaker. We will always check this on site.

For commercial 3-phase breakers and main breakers, the sizing and discrimination rules are more involved. See our 3-Phase Power Installation Singapore and Commercial Electrician Singapore pages for the larger scope.

Circuit Breaker Cost in Singapore

The breaker itself is cheap — usually $15 to $60 depending on brand, rating, and whether it is a single-pole MCB, double-pole, or RCBO. The labour to fit it is also small. So the deciding factor in total cost is usually whether the breaker swap is the whole job, or whether we have to do additional work to find out why it failed in the first place.

For full current rates, see our Electrical Services Price List Singapore page. As a rough guide for HDB and condo:

Single MCB like-for-like replacement — small job, often done in under 30 minutes on the same visit.
Add a new MCB + run a new circuit — needs DB capacity, new cable, and is a few hours of work.
Whole-DB re-look (every breaker replaced) — typically bundled with a DB upgrade.

We always give you a written fixed quote before any work begins. If we find something extra on site that genuinely affects safety, we pause, explain it, and quote separately before continuing.

Our Circuit Breaker Service Process

WhatsApp us a photo of the open DB box — this lets us identify the brand, model, and rating you already have, so we bring the right replacement. It also lets us give you an indicative quote in advance.
Phone triage — we will ask a few quick questions: which circuit is tripping, what happens when you reset, is there a burning smell, is anything visibly damaged. This 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 on the spot. If the breaker tests fine and the fault is the wiring or the 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 done to Singapore Standard CP5, and for new circuits or DB changes we issue a LEW-signed Certificate of Compliance.

Areas We Cover for Circuit Breaker Work

Islandwide Singapore, no travel surcharge. 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, and the East Coast. For landed properties and private estates, we have the same islandwide footprint and response times.

Why Homeowners Trust Us for Circuit Breaker Work

Licensed & LEW-endorsed — every meaningful job is signed off by a Licensed Electrical Worker registered with the EMA.
We test before we replace — you will not pay for a breaker you did not need.
EMA-approved components only — Schneider, ABB, Hager, Legrand, Clipsal, or equivalent. No unbranded substitutes.
Same-day or next-day slots for most breaker jobs.
Clean, polite, on-time — drop sheets, shoe covers, and a tidy site are the default.

FAQs

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 (the dangerous kind). RCBOs are more expensive, but for socket and water-heater circuits in HDB and condo, the personal safety benefit is significant. See our ELCB / RCCB Installation Singapore page for the broader safety-switch scope.

My MCB trips only at night — what could it be?

Usually one of three things: an appliance that is 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 is most likely to be.

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 always recommend replacing breakers that are 15+ years old as part of any DB upgrade.

Need a Circuit Breaker Replaced Right Now?

If your MCB will not stay on, is warm, buzzing, cracked, or tripping without load — or you are adding a new aircon, water heater, or socket circuit and need a new breaker — don’t risk a guess. A wrong-sized or unbranded breaker is a real fire hazard.

Contact TRUST ELECTRICIANS Singapore, operated by AASHIKA NUR PTE. LTD., for fast, safe, and properly sized circuit breaker replacement and installation.

Get in Touch

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30 ROBERTS LANE SINGAPORE (218309)

Email Address

sales@trustelectricians.com