Duties of high voltage electrical installation owners and operators

High voltage electrical installations

A high voltage (HV) electrical installation is a group of items of electrical equipment permanently connected that can be supplied with electricity from an electricity entity or from a generating source at voltages greater than 1000V ACRMS or 1500V ripple-free DC.

This includes electrical equipment associated with protection and earthing systems up to and including any low voltage cables and switchgear associated with HV electrical installations.

Persons conducting a business or undertaking (PCBU) at a premises with HV electrical installations or have management or control of a HV electrical installation have a duty to ensure the installation is designed, constructed, operated and maintained in accordance with the requirements of the:

• Electrical Safety Act 2002
• Electrical Safety Regulation 2013
• Managing electrical risks in the workplace code of practice 2021 (PDF, 1.25 MB)

The PCBU or person in control must ensure only licensed electrical workers perform or supervise electrical work and that the electrical worker is properly briefed on the task that is to be completed.  If electrical work is contracted to another PCBU then the PCBU performing the electrical work must hold an electrical contractor licence.

Section 221 of the Electrical Safety Regulation 2013 requires that an accredited auditor inspects HV electrical installations before connection or reconnection to a source of electricity. This is to ensure the installation, related electrical equipment and protective equipment comply with appropriate standards. For more information about these special requirements including a list of HV accredited auditors visit the Electrical safety audits page.

Design and construction

HV electrical installations must be designed and constructed to a standard that is consistent with good industry practice, with careful consideration of the ongoing safety of workers and members of the public, integrity of electrical equipment and risks to property.

HV electrical installations must comply with Australian Standard AS/NZS 3000 Wiring Rules and AS 2067 Substations and high voltage installations exceeding 1 kV a.c. If there is no existing Australian Standard for a piece of equipment, then International Electrotechnical Commission (IEC) standards could be used.

When procuring electrical equipment for private HV electrical installations it is important to verify that the equipment complies with the relevant standards and is deemed suitable for private electricity networks. Equipment that is deemed suitable for transmission or distribution entities does not mean it is suitable for private use.

The PCBU should have a good understanding of their HV electrical installation with accurate records of the installation including:

• schematic of the HV electrical installation
• underground HV cable location maps
• equipment compliance verification and certification records
• commissioning records
• maintenance manuals and plans.

Maintenance

PCBUs at a workplace with a HV electricity supply are responsible for ensuring their HV electrical installation:

• safely performs the functions for which it is designed and intended
• operates in accordance with the manufacturers’ requirements
• is maintained in good order
• does not create a hazard or cause interference to the electricity network operator’s distribution network in the event of a fault or malfunction.

Maintenance programs, frequencies and operations for particular item(s) of plant are best planned in consultation with the relevant manufacturers and, if required, the electricity network operator.

Maintenance plans for the HV electrical installation include (but are not limited to) the following items:

• power poles and overhead electric line infrastructure
• protection systems
• switchgear and transformer(s)
• earthing systems
• substation access security including warning signage.

The results of periodic inspections and examinations, including thermographic tests, may give guidance on the intervals between future inspections, examinations and overhaul operations with reference to particular operating conditions.

A person must not reconnect a high voltage electrical installation after electrical installation work or electric line work has been performed, unless the electrical work has been inspected by an accredited auditor.

It’s best practice to keep records of maintenance inspections and examinations including test results.

Operation

Best practice operation of a HV electrical installation includes the PCBU having a set of operational procedures incorporated into their site safety management plan or a specific HV electrical installation safety management plan. The procedures and plan are to ensure compliance with the requirements of the relevant legislation, codes, guides and Australian Standards including, but not limited to, the following matters:

• isolation procedures, including work permits, locking, testing and tagging
• personnel competencies and electrical access authorisations
• barriers for electrical, mechanical and personal protection
• access to rotating machines and discharging of deactivated apparatus
• earthing and short circuit requirements
• provision and use of personal protective clothing and equipment
• training
• worksite safety briefings
• internal and external communications including emergency personnel and electricity network operator
• contact details
• emergency and evacuation procedures.

Specific to accessing the electricity network, the processes for switching the HV electricity installation include, but are not limited to:

• ensuring each exposed part is treated as energised until it is isolated and not energised
• each high voltage exposed part is earthed after being deenergised
• operational equipment such as testing equipment and portable earthing devices are fit for purpose
• workers having skills/experience to operate the HV electricity installation
• having fault current control measures in place when operating switchgear.

Monitor and review

An effective safety management plan includes, but is not limited to:

• monitoring processes of workers undertaking HV work
• supervision processes for apprentices and young workers, noting the legislation restriction that a training person who has not finished six months of the person’s apprenticeship or training program are not permitted to do work in the immediate vicinity of a live high voltage exposed part or where there is a risk the training person could come into contact with a live low voltage exposed part. For further information refer to s. 279 of the Electrical Safety Regulation 2013
• having systems in place to report, receive and consider safety incidents, hazards and risks. This includes exercising due diligence in acquiring and keeping up to date on electrical safety matters, gaining an understanding of HV operations and associated hazards and risks. Refer to s.38A Duty of officers Electrical Safety Act 2002 and s.265 Duty of a PCBU to notify of a SEI or DEE
• ensuring site safety management plans or specific HV electrical installation safety management plans are relevant and up to date.