Singapore legislation
Regulation 42
of Workplace Safety and Health (Construction) Regulations 2007
Regulation 42
Electrical installations and equipment used underground or in confined space
It shall be the duty of the occupier of a worksite where any lighting, electric hand-held tools and inspection lamps and lights are used underground or in a confined space to ensure that —
(a)
the electricity supply for lighting and electric hand-held tools is provided by means of a step-down transformer having a secondary voltage not exceeding 110 volts centre point earthed; and
(b)
the electric hand-held tools and inspection lamps and lights are operated at a voltage not exceeding 55 volts between the conductor and earth.