An RCD (Residual Current Device) is the most important safety device in home electrics. Don’t ignore the importance of this little baby and ensure that you test it regularly.

An RCD is not a fuse. That function is provided by a Circuit Breaker (CB). CB’s are used together with RCD’s, fitted alongside each other in the consumer unit to safeguard your electrics. An RCD looks similar to a CB, but closer inspection will show an RCD has a test button.

An RCD is not a Surge Protection Device (SPD). It does not provide protection against destructive power surges that destroy electrical appliances. Click here to read about SPD’s.

So what the heck is an RCD and what does it do?

The primary function of an RCD is to prevent serious electric shock…. it can save lives!

An RCD monitors your electricity supply 24/7 and if it detects a leak of electricity, normally caused by damp or water ingress, it trips off and disconnects the electricity supply. This prevents a risk of electric shock from conductive items in the home like stainless steel draining boards, shower heads, taps, copper pipework, and other metal fixtures. The RCD will not allow you to switch the electricity supply back on until the fault is cleared or isolated.

You will find your RCD (note: there maybe more than one) in your consumer unit. Plus there may be additional RCD’s if you have secondary consumer units in the property. If you have a Jacuzzi, there may also be a separate RCD fitted to it.

In Spain an RCD is called an Interruptor Diferencial (ID) and all the sub-circuits of an electrical installation in a domestic dwelling must be protected with this device. The RCD must have a minimum rating of 30 milli-Amps.

If your RCD is faulty and your electrical system is not properly earthed (not uncommon in Spanish homes) then you and your family are at serious risk of electrocution. The bath and shower can become death traps.

#testyourRCD – Test your RCD every 3 months ….. it could be a life saver!


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Safety Tip: Every 10 years test arrange to test your RCD with a RCD test instrument to ensure it disconnects the electricity supply instantly within the specified time