RCDs located in electrical distribution boards and power points can and should also be tested on a regular basis. The standard detailing the requirements for these tests is covered in AS/NZS 3760:2010.
The tests carried out will be:
- Mechanical test (check that the RCD trips when pressing the test button)
- Tripping Time—A test current is injected into the RCD protected power point and the time to trip the RCD is measured both at zero degrees and 180 degrees of the sine wave cycle.
- Note that it is easier if safety switch numbers are placed on the powerpoints. As testing requires power to be cycled on and off a few times everything on those circuits will need to be turned off before testing.