RCD Testing

As part of your electrical appliance safety program, ALL the RCDs used in your workplace MUST be tested regularly to ensure they are working correctly.  The reason they need regular testing is dust, grit, lack of use or physical damage can cause the internal components to fail or the moving parts to “stick”, slow down or prevent it from tripping at all! You don’t want that happen.

The Standard AS/NZS 3760 sets out the maximum tripping time for a Type II RCD shall not be greater than 300 ms. That’s 0.300 of a second and is actually faster than you can blink!

There are two tests that need to be regularly performed;

The “push button” test is designed to provide an indication the RCD is working; you simply push the “test button” and the RCD should trip “without undue delay”.  This quick and simple test is commonly used with portable RCDs and should be performed daily or before each time you use the RCD – which ever is the longer. However it is not particularly accurate and should never be relied on as a reliable assessment of the RCD working correctly.

The “trip time” test using the “applied current” method is a far more accurate means of testing RCDs and is a required test under AS/NZS 3760. It measures the actual trip time and must be performed with equipment able to measure this to within +/- 8 ms ( 0.008 of a second ).

​