What is RCD testing?
A residual current device, or RCD, is a device that is design to stop you from getting a fatal electric shock if you touch a live wire or other live part. They offer protection that circuit breakers and ordinary fuses can’t, so it’s worth investing in RCDs if you haven’t got them already.
Since RCDs can save lives, it’s important to check that they are working regularly. You should have your RCDs tested by an electrician who will simulate a fault situation to see if they successfully cut off the power before anyone can be harmed by a strong electric shock.