How do you wire a GFCI or an RCD receptacle?

Answer 1

A GFCI has two sides: LINE and LOAD. The LINE side is where your incoming power to the receptacle is connected. This provides power to the receptacle, and allows the receptacle to disconnect power to itself if a ground fault occurs on something plugged into it. If you have more receptacles 'downstream' that need GFCI protection, you may power them from the LOAD side of the GFCI. This puts all devices wired to the LOAD side under the protection of the GFCI, as if they were plugged into the front of it with a cord and plug. When a ground fault occurs on a downstream receptacle, it will trigger the GFCI, which will disconnect power to all downstream receptacles as well as the devices actually plugged into the GFCI face. To make things easy on yourself, my professional opinion is to never wire anything to the LOAD side of a GFCI. That way when a ground fault trips the device, you don't have to hunt around to find out which GFCI is tripped (there may even be some you don't know about). We build commercial buildings and our crew policy is never to LOAD side anything. If the box has a set of wires coming in and going out to the next receptacle, just connect both sets to the LINE side. ----

If you do not understand the work well enough to accomplish it yourself properly and safely, don't try it. Consult a professional electrician, as they are proficient enough to do it properly and safely. When working on electrical circuits and equipment, make sure to de-energize the circuit you will be working on. Then test the circuit with a definitive means to make sure it is off (multimeter with metal tipped leads, voltage tester with metal tipped leads, etc., not a non-contact tester, which is non-definitive.)