What is the difference between 13A and 15A sockets?

13A, 15A and 20A at a glance

Plugs, sockets and switches in Singapore homes come in three common ratings, each for a different kind of load.

The plug details come from the CPSO's guide to plugs and socket outlets. The water heater rule is from MND's written answer to Parliament, and the isolator rule is from HDB's renovation guidelines for electrical works.

A 13A socket is the everyday outlet, and most appliances you buy will plug into one. The 15A and 20A ratings are for bigger loads.

What a 15A socket is for

The CPSO says the 15A 3 round-pin plug (Type M) is generally used by energy-intensive appliances such as air-conditioners. It also says 15A socket outlets should only be installed by qualified electrical workers, so this is not a DIY job.

In an HDB flat, the permit question depends on your main switch. HDB's electrical works guidelines say a new 15amps power point needs an HDB permit in flats provided with a 30amps main switch. Flats with a 40amps main switch, or flats upgraded under the Main Upgrading Programme (MUP) or Home Improvement Programme (HIP), need no permit. HDB also says appliances rated above 15amps are not allowed.

To find your main switch rating, look for the main switch label on your distribution board (DB box). Our guide on how to read your DB box shows where to look.

20A isolators and water heaters

In a written answer to Parliament in 2018, MND said water heaters should be connected to a 20 ampere socket switch, and not to a normal 3-pin socket that supports 13 amperes.

The CPSO's water heater safety tips say a water heater should not be connected to a 3-pin socket outlet. It should be wired directly to the mains through a double pole switch, and you should not use extension cords or multi-way outlets to power it. If yours runs from a plug today, our guide to water heater 3-pin plug safety covers what to check.

Isolators follow a separate rule. Under HDB's electrical works guidelines, a 20amps isolator is only allowed for aircon installation, and a new one needs an HDB permit in flats with a 30amps main switch. If your aircon installer says the unit needs a 20A isolator, our isolator installation cost guide explains what is involved.

Plugs that do not fit

The CPSO says 2-pin plugs (Type C) are for low-power, double-insulated appliances. To connect one to a 3-pin socket, use a suitable adaptor such as a fused conversion plug, and never force a 2-pin plug into a 3-pin socket.

German Schuko plugs are another matter. The CPSO says they are not suitable for use in Singapore: the pins stress the socket contacts, causing poor contact and overheating, and the side earthing strips cannot reach the local earth contact.

When you buy plugs or appliances, check for the SAFETY Mark. The CPSO says 13A and 15A plugs are Controlled Goods and must carry it.

If you run several appliances from one outlet through a power strip, read our guide on power strip overload first.

Adding a socket: who and what it costs

The Energy Market Authority (EMA) says adding, extending or replacing power points such as socket-outlets should be carried out or supervised by an LEW. EMA says electrical work in an HDB flat needs a Licensed Electrician, the class of LEW approved for loads of up to 45kVA.

Under HDB's electrical works guidelines, additional 13amps power points need no HDB permit, and there is no limit on the number, subject to your existing main switch rating. New wiring may not be embedded in walls, slabs or plaster, so it runs in surface trunking, above a false ceiling or behind carpentry. SP Services Form CS/5H endorsed by HDB must be submitted for testing of the new wiring.

FROM THE HOMEZYPRO DIRECTORY

Published socket and power point rates

For the most common unit (per job), the lowest published rates from 8 companies run from S$28 to S$90. Each figure is one company's own advertised rate with its conditions, not a market average or a quote.

See 9 published socket installation rates and sources

Lowest matching advertised rate per company, in SGD as published. "From" marks a starting price and ranges are shown in full. Check the source for minimums, GST and inclusions.

Company	Service as listed	Rate	Source
Skyteam Electrical Pte Ltd	Additional wall sockets (3-pin, 13A)	S$28 per job	skyteamelectrical.sg
AVV Engineering Pte Ltd	Replace Power Socket	From S$30 per job	avvelectrical.com
Electrician24 Singapore	Power Point Installation	S$60 to S$120 per job	electrician24.sg
Yong Jin Solutions Engineering Pte Ltd	Power socket installation (per point)	From S$60 to S$130+ per job	yongjinelectrical.sg
Mr Electrician Pte Ltd	Single Power Point	S$65	mrelectrician.sg
Saikon Contractors	Single 13A socket	S$75 per job	saikon.com.sg
Lito Electrical Service	Additional power socket point	From S$80 per job	litoelectrical.com
81 Electrical	Double power point (13A x2)	From S$90 per job	81electrical.com
Spower Electrician Services	Supply and install single or double 13A power socket (non-conceal)	From S$90 per job	spower.com.sg

9 companies publish a socket installation line. 8 of them price it per job, and their lowest published rates as printed run from S$28 to S$90 per job. The ninth company's S$65 line is printed without a unit. Lines differ in scope, so ask each company what its price covers.

See socket installation and our power point installation cost guide for prices, electrician costs for other jobs, or compare electricians.

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