What is an insulated socket?
Insulated sockets are similar to standard sockets but have a plastic coating surrounding them to insulate from electrical current.
The plastic coating used on insulated sockets can either be poly vinyl chloride (PVC) or nylon.
The plastic coating is often made up of two coloured layers: red and yellow. The colour acts as a visual indication to the user should the insulated cover become damaged, as the colour of the first coating will show through if the outer coating becomes damaged.
If the socket is damaged and the lower insulation coating can be seen, then the socket may not offer sufficient protection from electrical current and should be replaced.
Nylon vs. PVC
Nylon has several advantages over PVC when it comes to use on insulated sockets. Nylon bonds to the socket, and, when exposed to high temperatures, will not slip off the socket. Also, at very low temperatures, PVC can crack and fracture if dropped or subjected to impacts.
How are insulated sockets rated and tested?
Insulated sockets are tested to a safe live working current, for both an AC and DC electrical current.
To do this they are hung from a metal rail so they are partly submerged in a bath of water. When testing to a safe working limit of 1,000 volts, 10,000 volts are passed through the water in the bath for 3 minutes. If any electrical current makes it to the metal rail from which the socket is hung, then the insulation will fail the quality control check.
Can you get insulated socket sets?
Insulated sockets should only be used as part of an insulated socket set, which will contain an insulated turning tool. This is because the sockets themselves will not provide safe insulation from electrical currents, unless they are also used with other insulated tools such as insulated ratchets.
What sizes are available?
Insulated sockets will usually be sold in sets that contain sockets between 8mm - 25mm in metric sizes or 3/8"- 1" in imperial sizes. Insulated socket sets will also contain insulated extension bars and ratchets for use with the sockets. Insulated extension bars can be anywhere between 5" - 10" (127mm - 254mm) in length.
Who needs an insulated socket set?
Insulated sockets are specialist tools that most people including many electricians do not use.