Why it matters

Electricity gives no warning. A shock can stop the heart, throw a worker off a ladder or cause deep burns. Faulty wiring also starts fires.

The WSH Council lists the usual causes on site. Damaged cords and exposed wires top the list. Overloaded plugs, defective tools and wet conditions follow close behind. Most of these you can spot on a short walk round.

Who may do electrical work

Electrical repair and maintenance is not a job for whoever is nearest. In Singapore it belongs to a Licensed Electrical Worker (LEW). EMA licenses three classes: electrician, electrical technician and electrical engineer. Each class has limits on the load and voltage it may handle.

Your crew can still do a lot. They can check tools before use, report damage and keep their work area dry. They should not open panels, change fuses in distribution boards or rewire plugs on site equipment.

Know your LEW

Put the name and phone number of the appointed LEW on the site notice board. Workers then call the right person instead of trying a fix themselves.

Order of controls

Start at the top of this list. Drop down only when the step above is not possible.

  • Work dead. Switch off and isolate the supply. Live work is the exception and needs strong justification.
  • Lock it and tag it. Each worker fits a personal lock to the isolator. A tag says who locked it and why.
  • Engineer the risk down. Use RCD-protected supply, battery tools, and low-voltage equipment in wet or cramped spaces.
  • Set the rules. Write a safe work procedure, train people on it and keep unauthorised people out of switch rooms.
  • PPE last. Insulating gloves, rubber-soled safety shoes and non-conductive clothing add a layer. They do not replace isolation.

Lock-out/tag-out, step by step

Lock-out/tag-out (LOTO) stops a machine or circuit from being switched on while someone works on it. The WSH Council sets out a minimum sequence. Here it is in plain terms.

  • Tell the people who use the equipment that it is going down.
  • Switch the equipment off at its normal controls.
  • Open the isolating device, such as a circuit breaker or disconnect switch.
  • Fit a lock and a tag to each isolation point. The tag names the person, the reason and the expected finish date.
  • Release or block stored energy. Discharge capacitors. Bleed air and hydraulic lines. Block parts that could fall.
  • Try to start it. Press the start button and confirm nothing moves. Then return the control to off.
  • Prove dead with a tested voltage tester where conductors are exposed.
  • Do the work. When finished, clear tools, refit guards and count people out.
  • Each worker removes their own lock. Then restore power and test the equipment.
One person, one lock

When several people work on the same equipment, use a hasp or group lock box. Every worker adds their own lock. Power cannot return until the last lock comes off.

Portable tools and temporary supply

Most site shocks come from everyday gear: extension reels, grinders and temporary lighting. Check each item before use. Look for cut sheaths, exposed cores, cracked casings, scorch marks and missing earth pins.

Protect circuits with a residual current device (RCD). UK HSE guidance says a device rated at 30 mA or less can save a life in some shocks. Press the test button regularly. An RCD does not make live work safe, so still isolate before you work on a circuit.

Do not daisy-chain multi-way adaptors. Keep cables off wet floors and out of walkways. Lift them clear of vehicle routes or protect them with cable covers.

What the rules require

The WSH (General Provisions) Regulations set the main duties for occupiers in Singapore. Regulation 14 covers electrical installations and equipment. They must be of good construction and free from defects. They must be used and maintained so they are safe. The occupier must also take reasonably practicable steps to protect people from electric shock.

Regulation 16 covers lock-out procedures. The occupier must set up and run them for inspection, cleaning, repair and maintenance work. They apply to any plant, machinery, equipment or electrical installation that could injure someone if switched on by accident. Every worker doing that work must be fully instructed on the procedure first. The regulation defines lock-out as isolating, disconnecting or discharging all energy sources and preventing accidental start-up.

Under EMA rules, the licensee of an electrical installation must appoint an LEW of the right class. Only an LEW may do electrical work on it. EMA's handbook says licensed installations on construction worksites must be inspected by the appointed LEW at least once a month.

Legal requirement

Occupiers must establish and implement lock-out procedures and fully instruct workers on them before maintenance starts. Source: WSH (General Provisions) Regulations, reg 16.

Common mistakes

  • Switching off at the machine but not at the isolator. A stop button is not isolation.
  • Skipping the try-start. A wrong breaker looks exactly like the right one.
  • One lock for a whole team. The first person to finish removes it while others are still inside.
  • Tags with no name or date. Nobody knows who to ask before removing them.
  • Taped-up cables kept in service. Tape is not insulation repair.
  • Leaving cord-and-plug machines unplugged but within reach. Someone plugs them back in. Use a plug lockout box.
The wrong breaker

Label every board and breaker. Then test before you touch. The tester is cheaper than a funeral.

If someone gets a shock

Do not touch the person while they may still be live. Cut the power at the switch or isolator first. If you cannot, push the source away with something dry and non-conductive, like a wooden broom handle.

Call 995 for an ambulance. Start CPR if the person is not breathing and you are trained. Every electric shock needs a medical check, even if the worker says they feel fine. Report the incident and keep the equipment out of use until the LEW has checked it.

Use it on site: the electrical safety & lock-out/tag-out checklist and the toolbox talk to brief your crew.

Sources

  1. Electrical Safety, WSH Council.
  2. Workplace Safety and Health (General Provisions) Regulations (copy hosted by NUS), Ministry of Manpower (via NUS).
  3. WSH Insights: Working Safely with Machines: Strengthening Lockout Tagout Practices (April 2026), WSH Council.
  4. Handbook for Application of Electrical Installation Licence, Energy Market Authority.
  5. Safe Electrical Maintenance Work checklist, WSH Council.
  6. Electrical safety FAQs, UK HSE.

This is practical guidance, not legal advice. Laws and codes of practice change; always check the current official text and your site's own procedures.