Western Power has issues clarification around what is needed when replacing a main switch. This has been one of the most common questions MEA has been receiving from WA Master Electricians in recent weeks. 

The end user is only able to use the supply they’ve been paying for, and this is to be limited by the use of a circuit breaker as the main switch. The standard supply sizes are laid out in the WASIR Definitions 1.1 that read as follows:

1.1 Definition (WASIR)

Standard supply is defined as 240 volt single-phase (+/- 6%) or 415 volt three-phase (+/- 6%) for:

Perth metropolitan and major regional centres within the SWIS:

• 63 amps single-phase (240 volts); or
• 32 amps per phase, three-phase (415 volts); and

2. Rural centres and connections within the SWIS (Note 1):

• 32 amps single-phase (240 volts);or
• 32 amps three-phase (415 volts); or
• 20 amps per phase, multi-phase, (480 volts); and
• maximum size of consumer mains cable shall not exceed 35 mm2.

Notes:

1. Subject to service availability
2. For network connection generation capacity limits, refer to Section 15 and Western Power’s embedded generation EG technical requirements.

The 20amps per phase, multi-phase (480 volts) has been increased up from 16amps.

The reasons stated by Western Power for the enforcement now is due to load creep on the network, and the possible future issues arising with the increased use of EV Charging and Solar systems.

Western Power is working on guidance material to hopefully assist contractors better understand these changes. We will notify you when this becomes available.

If you have any questions regarding technical issues on the job, Master Electricians have unlimited direct access to the MEA Technical Hotline. Phone direct on 1300 889 198.

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