What is a Licensed Electrical Worker (LEW)? Singapore's System Explained

The Short Answer

A Licensed Electrical Worker (LEW) is a person licensed by Singapore's Energy Market Authority (EMA) to design, install, repair, maintain, operate, or test electrical installations. Under the Electricity Act, most electrical work in Singapore must be carried out by — or under the direct supervision of — a LEW. It is not a company licence; it is a personal licence held by an individual engineer or technician who takes legal responsibility for the work.

The Three Classes of LEW

EMA issues three classes of electrical worker licence, each with a different scope:

• Licensed Electrician — may carry out electrical wiring work on installations up to 45 kVA, single-phase or three-phase low voltage. Typically covers homes, shops, and small offices.
• Licensed Electrical Technician — may design, install, and maintain electrical installations up to 150 kVA at low voltage (some grades up to 1 MVA). Covers most small-to-medium commercial premises.
• Licensed Electrical Engineer — the highest class. May take charge of installations of any capacity, including high-voltage (HV) systems such as 22kV switchgear and transformer substations. Required for industrial plants, data centres, hospitals, and large commercial buildings.

Each class also has grades that set the maximum size of installation the licensee may take charge of. When you appoint a LEW, their licence class and grade must match your installation's capacity.

When Do You Legally Need a LEW?

• New electrical installations — design, installation, testing, and the application for a licence or supply connection must all be done by or under a LEW.
• Modifications and additions — adding distribution boards, rewiring, or increasing loading requires LEW supervision and certification.
• Premises holding an Electrical Installation Licence (EIL) — you must appoint a LEW to take charge of the installation on an ongoing basis, with duties including periodic inspection and certification.
• Periodic testing and inspection — the test reports EMA and SP Group accept must be signed by a LEW.
• High-voltage switching operations — only appropriately licensed engineers may perform or supervise HV switching.

Routine, non-electrical activities — changing a light bulb, plugging in equipment, resetting a tripped breaker once — do not require a licence. But the boundary is narrower than most people think, and unlicensed electrical work is an offence under the Electricity Act.

What Does "Taking Charge" of an Installation Mean?

For licensed installations, the appointed LEW is responsible for the ongoing safety of the entire electrical installation. In practice this means they:

• Carry out (or supervise) maintenance and periodic inspections
• Certify the installation for licence renewal each year
• Review proposed modifications before work is done
• Keep single-line diagrams and records up to date
• Act as the responsible person EMA contacts about the installation

How to Appoint the Right LEW

• Match the licence to your installation — check the class and grade against your approved load. An electrician's licence cannot cover a 1,000 kVA factory.
• Ask about response times — your LEW is who you call when something trips at 2am. Ask what their emergency arrangements are.
• Look for relevant experience — a LEW who mainly does residential work may not know your industry's standards and quirks.
• Confirm the licence is current — EMA maintains a public register of licensed electrical workers you can check.

How RES Engineering Services Can Help

Our team includes Licensed Electrical Engineers who act as the appointed LEW for industrial, commercial, and institutional premises across Singapore — handling periodic inspections, licence renewals, testing, and day-to-day electrical advice. If your current LEW is retiring, unresponsive, or your installation has outgrown their licence grade, talk to us about a LEW takeover — the handover is simpler than most building owners expect.