On top of the HSE Act and Regulations and the Electricity Act and Regulations:
Guidelines for the provision of facilities and general safety and health in Commercial and Industrial Premises (to meet the requirements of the Health and Safety in Employment Act 1992 and Regulations 1995):
Portable electric equipment:
Where any portable electric power-driven equipment is provided, the employer should ensure that all such equipment:

Guidelines for the provision of facilities and general safety and health in the Construction Industry (to meet the requirements of the Health and Safety in Employment Act 1992 and Regulations 1995):
Inspection of Equipment:
All electrical tools and equipment should be inspected prior to their first use and thereafter at least at 3-monthly intervals
Inspection and testing to AS/NZS 3760 will ensure appropriate tests and inspections are carried out and that records are kept for use in future if required.

Ministry of Education Property Handbook:
On top of the HSE Act & Regulations and the Electricity Act and Regulations, the MoE school property management handbook section 7.7 states:
“Boards have a responsibility to ensure that electrical equipment is installed, maintained and used safely as required by the Integrated Electricity Regulations 1997/2004”
And
“AS/NZS 3760:2003 In-service safety inspection and testing of electrical equipment describes a minimum standard regime for testing electrical equipment”
And
“Following the regime provides Boards with a defence in the event of an accident involving electrical equipment”