Which electrical work needs an LEW?

Work that must be done by an LEW

EMA says electrical work in your home should be carried out or supervised by a Licensed Electrical Worker. Its page on engaging licensed electrical workers lists three kinds of work:

• Installing, repairing or modifying electrical wiring.
• Adding, extending or replacing power points, such as socket-outlets, switches and lighting points.
• Repairing or replacing consumer control units or circuit breakers.

EMA's electrical safety guidance defines electrical works broadly: any rewiring, modification, alteration, repair or replacement to the electrical installation.

If you are planning socket installation or a DB box replacement, ask the company which LEW will carry out or supervise the work.

Licensed electrician or another class of LEW?

The class of LEW you need depends on the scale of the installation, according to EMA's page on engaging licensed workers. EMA says electrical work in an HDB flat needs a Licensed Electrician, the class of LEW approved for loads of up to 45kVA.

If you are not sure which class your job calls for, ask the company before work starts.

What you can safely do yourself

Many small jobs suit handyman services, but wiring, power points and the DB box stay with an LEW. The checks below do not open up the fixed installation.

Test the RCCB every month

The RCCB cuts off electricity when it detects a current leakage that could lead to an electric shock. EMA's electrical safety page says to test it once a month. It is usually in the DB box, as a switch with a "Test" button.

HDB's guide to electrical accessories and wiring says pressing the test button (labelled T) should switch the RCCB off; if not, it may be defective. Switch off sensitive equipment such as computers first, and reset the RCCB after testing. If it malfunctions, engage a licensed electrician to replace it.

Fit the right plug fuse

HDB says a 13A plug should have a 13A fuse, so unplug the appliance and replace a blown fuse with one of the same rating. HDB links overheated plugs and frequently blown fuses to loose connections, overloaded circuits or broken cables. If fuses keep blowing, ask an LEW to check.

Look after cords and power points

EMA says to replace cords with broken or frayed insulation instead of joining them with insulation tape. Do not overload power points or "piggy-back" several plugs into one socket with double adaptors, as overloading can lead to over-heating and start a fire.

For a fuller set of checks, see the home electrical safety checklist.

How to check a licence

An electrical work licence is quick to check before anyone opens a socket or the DB box. According to EMA's guidance on engaging LEWs, every LEW carries a licence card with a photograph, name, identity card number and licence number, and you should verify the card before any electrical work starts. You can also look a worker up on EMA's ELISE portal or call 6835 8075, as EMA's safety page explains.

If a company sends a team, ask which LEW will carry out or supervise the work, then check that person's card. See how to check a licensed electrician for more.

Testing and certification

EMA's electrical safety guidance says the LEW also inspects and certifies that the installation is safe before supply is turned on. New wiring, rewiring and extensions must also be tested by an authorised officer from SP Services Ltd before supply can be turned on.

For rewiring an HDB flat, HDB says the appointed LEW must submit an SP Services form CS/5H, endorsed by HDB, to SP Services and apply for testing of the completed works. HDB gives the estimated average lifespan of a PVC electrical cable as about 25 years, and an LEW can check your wiring and advise whether it needs replacing.

The price of rewiring, or any other electrical job, depends on the work involved. See electrician costs in Singapore for what companies publish.

When to stop and call a professional

Call an LEW if you notice any of these:

• A burning smell near a socket, switch or the DB box.
• Burnt marks at a socket.
• Breakers that trip again and again.
• An RCCB that will not reset, or does not switch off when you press T.
• Water near sockets, switches or the DB box.

HDB links burnt marks at a socket to a plug not fully inserted or an overloaded circuit, and says an MCB trips when there is an overload or short circuit. EMA lists ageing or exposed wires, faulty appliances and damaged insulation as causes of the current leakage that trips an RCCB.

Questions