Caecilius expressed precisely :

Does anyone know if it's possible to hire RCD testers for short
periods at a reasonable rate? When I've looked, most hire shops direct
me to a PAT tester which isn't what I'm looking for. I don't want to
buy one for a single project.

Surely a new RCD would be cheaper.

As harry said, you can adjust the current trip threshold with just resistors. If you then set trip current with capacitors instead, you'd be closer to real world conditions and can see if it filters out such transients effectively, as it should.

The only thing that doesn't test is whether it trips within prescribed time limits, but that has not too much to do with your problem.

Or you can just replace the RCD.


NT