How to Test & Tag a Portable RCD

Testing Portable RCDs, commonly known as portable safety switches, involves more than simply pressing the test button. You need to check that the RCD operates correctly, measure its trip time and complete the required electrical safety tests before it can be passed and tagged.

In the video below, we demonstrate the RCD operating tests using a Seaward PAC3760 DL, including the manual push-button test and trip-time testing at 0° and 180°.

Testing of an RCD should involve:

• Push button test
• Leakage current testing
• RCD trip-time tests

Start With a Visual Inspection

As with any electrical equipment, testing should begin with a thorough visual inspection.

Look for damage or deterioration - such as cuts, cracking, exposed conductors, loose components and overheating. Make sure the inspection also includes the protective cover.

You can also see our Visual Inspection Checklist for more information on what to look for before electrical testing begins.

Perform the Push-Button Test

First, connect the portable RCD to mains power.

Once it’s connected, press the TEST button.

The RCD should trip immediately when the button is pressed. If it does not trip, it has failed the manual push-button test and should not be passed.

Reset the RCD before continuing with the remaining tests.

Test the RCD Trip Time

The next part of the process involves two trip-time tests: one at 0° and one at 180°.

These tests measure how quickly the RCD disconnects the power, with the result displayed in milliseconds (ms). You will need to select the RCD test that corresponds with the rating of the RCD being tested. 

For the 30 mA RCD used in this demonstration, the trip time must not exceed 300 ms.

The RCD will trip during each test and needs to be reset before the next test is performed. 

If the portable RCD has multiple sockets, the required testing needs to be carried out for each outlet and you’ll need to record in a log the highest trip time value for all outlets tested.

Leakage Current Testing

A leakage current test is also carried out as part of testing the portable RCD.

This test measures the amount of current leaking from the equipment while it is operating and helps determine whether the equipment remains electrically safe.

The exact setup and testing procedure can vary depending on the portable appliance tester being used, so always follow the appropriate procedure for your tester.

What Happens If a Portable RCD Fails?

If the portable RCD fails the visual inspection, manual push-button test, leakage current test, trip-time testing or any other required electrical safety check, it should not be passed or returned to normal use.

The equipment should be clearly identified as failed and removed from service until it has been appropriately repaired, replaced or otherwise dealt with.