RCD Testing: How Often and What the Rules Say in SA

RCD testing: how often, and what the rules say in South Australia

In a South Australian workplace, RCDs are tested to AS/NZS 3760: a push-button test every 6 months for most sites and a trip-time test every 12 months, with construction sites on a tighter monthly cycle. Homes have no mandated interval, but pressing the test button every 3 months is the standard advice and it takes 10 seconds. Here's what each test is, who has to do it, and what the record has to say.

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What an RCD is for

A residual current device, called a safety switch on most Australian switchboards, watches the current going out on the active and coming back on the neutral. If they differ by more than 30 milliamps, which means current is leaking somewhere it shouldn't (through a damaged appliance, through water, through a person), it trips in a fraction of a second. It's the single device that most reduces the chance of a fatal shock, and like anything mechanical it can seize if it's never exercised.

The 2 tests

The push-button test is the button on the front of the device. Pressing it puts a small imbalance through the RCD and it should trip immediately. This checks the mechanism moves. Anyone can do it.

The trip-time test uses an instrument to inject a precise fault current and measure how many milliseconds the RCD takes to open. AS/NZS 3760 sets the limit (300 milliseconds for a standard 30 mA device, and much less at higher test currents). A device can pass the button test and fail the trip-time test, usually because it's old or has been through a fault. This test needs a licensed electrician with a calibrated tester.

How often in a workplace

Environment	Push-button test	Trip-time test
Offices, retail, hospitality	6 months	12 months
Factories, workshops, warehouses	6 months	12 months
Construction and demolition sites	Monthly (portable RCDs daily or before use)	12 months, or 3 months for portable
Medical patient areas (AS/NZS 3003)	As per that standard	12 months

Those are the intervals from the current edition of AS/NZS 3760. Some sites run tighter cycles under their own safety systems or their insurer's conditions, and a maintenance agreement usually folds RCD testing into the same visit as the emergency lighting and the test and tag round.

How often at home

There's no legislated testing interval for RCDs in South Australian homes. What SA regulators and every electrician recommend is to press the test button on each RCD every 3 months, and to get a licensed electrician to check the board if one won't trip or won't reset. If your home has no RCDs at all, which is common on switchboards from before the early 1990s, that's a switchboard upgrade conversation and the most worthwhile electrical spend a household can make.

What the record has to show

The date, the site and who did the test (name and licence number for trip-time tests).
Each RCD identified: board, circuit, rating.
The result: pass or fail, and the measured trip time in milliseconds.
What was done about any failure.
When the next test is due.

Our RCD testing service delivers that record on the day, with the next-due date scheduled. A page on file beats a conversation with an inspector every time.

Need this done rather than read about? See rcd testing or request a free quote.

Questions we get on this

Is RCD testing a legal requirement in South Australia?

For workplaces, the Work Health and Safety Regulations require electrical equipment to be maintained safe, and AS/NZS 3760 is the accepted way to show that for RCDs and portable equipment. For homes there's no mandated interval. We're electricians, not lawyers, so check with SafeWork SA for your specific obligations.

What happens if an RCD fails the trip-time test?

It's replaced. A slow RCD provides less protection than the rating implies, and the fix is a new device on the same circuit, usually done on the spot.

Can I do the trip-time test myself?

No. It needs a calibrated instrument and a licensed electrician, and the record has to carry a licence number. The push-button test you can and should do yourself.