Guide to using different types of RCDs - Type AC versus Type A

In Australia, Type AC Residual Current Devices (RCDs) are the most commonly used type of RCD. Type AC RCDs are suitable for tripping residual sinusoidal alternating currents.

However, with the increased uptake of electronics, renewable energy and other emerging technologies, there has been an increase of d.c. waveforms on the a.c. supply. Amendment 2 of AS/NZS 3000:2018 clause 2.6.2.2.1 is now recommending the use of Type A RCDs which also trip residual sinusoidal alternating currents and residual pulsating direct currents.

The installation of Type AC RCDs will not be permitted in Australia after 2 April 2023 as per the amended clause 2.6.2.2.2 of AS/NZS 3000:2018. The amendment to this clause also requires RCDs located beside or incorporated into a socket-outlet to interrupt all live (active and neutral) conductors.