Electrical Wire Colour Codes in Singapore: Old vs New (SS 638)
In Singapore today, the live wire is brown, the neutral wire is blue, and the earth wire is green-and-yellow — the colours set out in Singapore Standard SS 638, which follows the international IEC harmonised code. Before 1 March 2009, Singapore used the old colours: red for live, black for neutral and green for earth — and that older scheme is still inside the walls of many HDB flats, condos and landed homes built before 2009. This guide covers both codes side by side, the three-phase colours, why mixed-era wiring is genuinely dangerous, and when rewiring makes sense.
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What are the current electrical wire colours in Singapore?
Singapore's current wiring colours follow the IEC harmonised colour code, adopted locally through the national wiring standard — today that is SS 638 (Code of Practice for Electrical Installations), which replaced the older CP 5. The Energy Market Authority (EMA) made the new cable colours mandatory for all new electrical installations from 1 March 2009, after a transition period.
For the standard single-phase 230V / 50Hz supply found in most Singapore homes:
- Live (L): Brown — carries current from the supply to the appliance. Touching it is dangerous.
- Neutral (N): Blue — the return path that completes the circuit.
- Earth (E): Green-and-yellow stripes — the protective conductor that carries fault current safely to ground so the RCCB or breaker can trip.
These are the colours you will see in any flat wired or rewired after 2009, including all BTO flats and newer condos.
What were the old wiring colours before 2009?
Installations completed before 1 March 2009 typically use the old colour code, inherited from the British system:
- Live: Red
- Neutral: Black
- Earth: Green (plain green, or green-and-yellow in some later installations)
You will still find these colours in older HDB flats, walk-up apartments, pre-2009 condos, landed houses and shophouses that have never been fully rewired. The old colours are not illegal — existing installations did not have to be ripped out when the code changed. But every new circuit, extension or rewiring job done after March 2009 must use the new colours, which is why many older homes now contain a mix of both codes.
Old vs new wire colour codes: comparison table
| Conductor | New code (SS 638, from 1 Mar 2009) | Old code (pre-2009) |
|---|---|---|
| Live / Phase L1 | Brown | Red |
| Phase L2 (three-phase) | Black | Yellow |
| Phase L3 (three-phase) | Grey | Blue |
| Neutral | Blue | Black |
| Earth (protective conductor) | Green-and-yellow | Green |
Read that table twice and you'll spot the trap: blue and black swapped meanings. In the old code, black was neutral and blue was a live phase. In the new code, blue is neutral and black is a live phase. In a building with mixed-era wiring, colour alone cannot tell you whether a blue or black wire is safe to touch.
What are the three-phase wire colours in Singapore?
Most HDB flats run on single-phase 230V supply, but larger landed homes, homes with high electrical load (multiple aircon systems, EV chargers, electric hobs) and commercial units use three-phase 400V supply. Under the current code, the three phases are brown (L1), black (L2) and grey (L3), with a blue neutral and green-and-yellow earth. Under the old code, the phases were red, yellow and blue with a black neutral — which is exactly why old switchrooms are labelled "R-Y-B".
If you are upgrading from single-phase to three-phase supply — common when adding multiple aircon systems or an EV charger — the new circuits must be wired in the current colours by a licensed electrical worker, and the DB box usually needs to be upgraded at the same time.
Why do wire colours matter for safety?
Colour coding exists so that anyone opening a switch, socket or DB box can immediately tell which conductor is dangerous. Getting it wrong has real consequences:
- Reversed polarity: if live and neutral are swapped at a socket, an appliance can remain energised even when its switch is off, because the switch is interrupting the neutral instead of the live.
- Mixed-era confusion: in a pre-2009 flat that has had partial rewiring, a black wire might be old neutral or new live phase, and a blue wire might be new neutral or old phase. Electricians treat every conductor as live until proven otherwise with a voltage tester — homeowners should never trust colour alone.
- Broken earth path: if the earth conductor is misidentified or left disconnected, a fault inside a metal-bodied appliance (kettle, washing machine, water heater) can make the casing live without tripping anything.
- Tripping faults that hide: miswired circuits are a common root cause behind recurring power trips that seem random — the RCCB is doing its job, but the underlying wiring fault never gets found.
Do I need to rewire old red-black wiring?
Not because of the colours alone — pre-2009 installations are allowed to keep their original wiring. What matters is the condition of the wiring, not its colour. Rewiring is strongly recommended when you see any of these:
- Insulation that is brittle, cracked, discoloured or sticky — PVC insulation degrades with age and heat
- Wiring roughly 25-30 years old or older, especially if it has never been inspected
- Frequent unexplained power trips, flickering lights or warm switch plates
- An old DB box with rewireable fuses or no RCCB (earth-leakage protection)
- Scorch marks, a fishy or burning smell near sockets or the DB box — treat this as urgent and call a 24-hour electrician
- A renovation that adds new circuits — extending undersized old wiring to feed modern aircon, induction hobs or water heaters overloads it
Modern domestic circuits in Singapore typically use 2.5mm² cable for 13A socket circuits and 1.5mm² for lighting. Many older flats were wired for the appliance loads of the 1980s, so even healthy-looking old wiring can be undersized for today's usage.
What does rewiring or electrical work cost in Singapore?
These are FixMove's 2026 reference ranges for the jobs most relevant to old wiring. Full breakdowns are on the electrician cost guide and the DB box upgrade cost page.
| Job | Typical price (2026) |
|---|---|
| Site inspection (1-hour diagnostic) | S$60 — waived if you proceed with the repair same visit |
| Power-trip diagnosis | S$60 – $150 |
| Socket replacement (13A double) | S$60 – $120 |
| MCB / breaker replacement | S$120 – $180 per breaker |
| RCCB (ELCB) replacement | S$180 – $280, including trip-current testing |
| New power point (surface trunking, no hacking) | S$120 – $220 |
| DB box rewire (new MCBs + RCCB) | From S$250 |
| DB box upgrade — 6-way | From S$380 |
| DB box upgrade — 12-way | From S$580 |
| DB box upgrade — 18-way | From S$780 (extra MCBs from S$40 each) |
Whole-unit rewiring is quoted per job because it depends on the number of points, whether conduit is concealed or surface-run, and how much hacking and making-good is involved. Send a photo of your DB box and floor plan on WhatsApp for a written quote before anyone visits.
Can I do my own electrical wiring in Singapore? (DIY legal limits)
Singapore regulates electrical work tightly. Under the Electricity Act, administered by EMA, electrical wiring work must be carried out by, or under the supervision of, a Licensed Electrical Worker (LEW). In practice the line for homeowners is:
- Generally fine to DIY: replacing a light bulb, replacing the fuse in a plug top, plugging appliances in and out, resetting a tripped MCB or RCCB.
- Requires a licensed electrical worker: anything involving fixed wiring — adding or moving power points, extending circuits, replacing a DB box or its breakers, rewiring, and new circuits for aircon, water heaters or EV chargers.
Carrying out electrical work without the required licence is an offence under the Electricity Act, and unlicensed work can also void fire insurance claims and create problems at HDB resale or renovation-permit stage. EMA maintains a public register of LEWs at ema.gov.sg — FixMove arranges works requiring an LEW through EMA-licensed personnel, and you can request the assigned worker's licence number before work starts.
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Related Reading
- Electrician Cost Singapore — full 2026 price list for sockets, MCBs and rewiring
- Electrical Services Singapore — trips, sockets, lighting and wiring repairs
- Power Trip Electrician — why your RCCB keeps tripping and how it's traced
- DB Box Upgrade Cost — replacing old fuse boxes with MCB/RCCB units
- 24-Hour Electrician Singapore — for burning smells, sparking and total power loss
- FixMove Blog — all home-services guides
FAQ
What colour is the live wire in Singapore?
Brown. Under the current Singapore Standard SS 638 (aligned with the international IEC code), the live wire is brown, neutral is blue, and earth is green-and-yellow. In installations wired before 1 March 2009, the live wire is red instead.
Is a blue wire live or neutral in Singapore?
Under the current code, blue is neutral. But in the OLD pre-2009 three-phase code, blue was a live phase conductor. In an older building a blue wire can be live — always test with a voltage tester, never trust colour alone.
When did Singapore change its wiring colours?
The new international (IEC harmonised) cable colours became mandatory for new electrical installations in Singapore from 1 March 2009, under EMA's implementation of the change. The governing standard today is SS 638, which replaced CP 5.
Do I have to rewire old red and black wiring?
No — existing installations using the old colours remain legal. Rewiring is recommended when the insulation is brittle or discoloured, the circuits trip frequently, the DB box has no RCCB, or the wiring is roughly 25-30+ years old. A full DB box rewire starts from S$250.
Can I do my own electrical wiring in Singapore?
DIY is legally limited to simple tasks like replacing a light bulb or a plug-top fuse. Under the Electricity Act administered by EMA, electrical wiring work — new points, extending circuits, rewiring, DB box work — must be carried out by or under the supervision of a Licensed Electrical Worker (LEW).
What are the three-phase wire colours in Singapore?
Current code: L1 brown, L2 black, L3 grey, neutral blue, earth green-and-yellow. Old pre-2009 code: L1 red, L2 yellow, L3 blue, neutral black. Note that blue and black swap meanings between the two codes.
Published: 11 June 2026 · Updated: 11 June 2026 · By FixMove Electrical Team — works requiring a Licensed Electrical Worker are arranged through EMA-licensed personnel. Sources: Energy Market Authority (EMA), Singapore Standard SS 638.