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What are TR25 and LEW for EV Chargers in Singapore?

What are TR25 and LEW for EV Chargers in Singapore?


The required EV charging standard is TR25 and can either be AC or DC chargers. In installing these charging systems, operators are required to engage a Licensed Electrical Worker (LEW). Thus, TR25 and LEW are essential standards and requirements for EV chargers and EV charging operators in Singapore

Technical compliance checklist for EV charging system (TR25:2016)

A nationwide electric vehicle (EV) charging standard Technical Reference for EV Charging Systems (TR25) was established for the EV Charging System in Singapore. The TR25 sets out the technical standards and safety precautions for the design, installation, and operation of chargers. The latest version of the technical reference is TR25:2016.

TR25:2016 specifies mandatory safety technical requirements for EV charging systems. The Technical Reference is to be read together with SS 638 (formerly SS CP 5), Code of Practice for Electrical Installation and the relevant International Electrotechnical Commission (IEC) standards. The intention is to protect persons and properties against electrical hazards. (Find  out more about IEC standards)

Source: LTA (n.d). Testing of EV charging system [infographic].

Requirements for installation and maintenance of EV charger

EV Charging Operators are required to engage LEW to install, test, and certify the fitness of EV Supply Equipment (EVSE) installation. Before its installation, the LEW shall check that the EVSE is issued with a Letter of No Objection (LNO) to ensure that it complies with TR25:2016, the relevant International Electrotechnical Commission (IEC) standards and the essential tests.

As operators of the EVSE, EV Charging Operators are responsible for the safe use and operation of the EV Charging Systems. Regular maintenance, electrical safety inspection and testing shall be carried out on the EVSE according to TR25:2016 Amendment No. 1 (May 2020). A LEW has to be engaged to periodically inspect and test the EVSE.



LTA. (n.d.). LTA | Industry & Innovations | Technologies | Electric Vehicles | Information and Resources. Retrieved July 23, 2021, from

EMA. (n.d.). EMA | Technical Compliance Checklist For Electric Vehicle Charging System. Retrieved July 23, 2021, from