Plastic contra safety plug

The female counterpart to the plug, in a plastic housing with an earth contact. This is what a device plugs into. Fitted to your own cable.

Which end faces the socket

When making an extension lead this is the question that matters, and the answer is not arbitrary.

The end going into the wall socket takes the plug, with pins. The end the device plugs into takes this trailing socket, with holes. That is the way round it goes, always.

The reason is that an exposed pin must never be live. Put the trailing socket on the mains side and the plug on the appliance side, and you have a lead with two protruding pins carrying voltage the moment the other end goes into the wall. That is lethal, and it happens more often than you would think on home-made leads.

Fitting

Same rules as the plug: brown is live, blue is neutral, green and yellow is earth, cut the earth core a few millimetres longer, and clamp the strain relief on the outer sheath rather than the cores.

If you are not certain, have it done by someone who knows the trade.

Plastic or rubber

This is the plastic version: lighter and cheaper, fine for a lead that stays where it is put. For a lead that runs across a floor, gets moved, or can take knocks, the rubber trailing socket is the better choice.

Technical Specifications:

• Housing: plastic
• Type: earthed trailing socket (female)
• Assembly: fitted to your own cable
• Counterpart: earthed plug
• Also available in: rubber

Frequently asked questions

Which end goes in the wall socket? The plug, with pins. This trailing socket always goes on the appliance side.

Why does that order matter so much? Because an exposed pin must never be live. Fitted the other way round, that is exactly what you get.

Same colour code as the plug? Yes: brown live, blue neutral, green and yellow earth, and the earth slightly longer.

Plastic or rubber? Plastic for fixed setups, rubber if the lead gets moved or can take knocks.