A separate ring main is usually installed on every floor of a given property to make sure things are kept safe and it is only when for example a spur socket additional socket is added on an upstairs ring main to feed a socket or light on a downstairs circuit that things can get tricky.
Socket ring main cable size.
It is not particularly difficult to extend a ring main but you must remember that certain rules apply about the floor area and length of cable one ring main may serve and use.
For the rules that govern how tis can be dne please.
Ring circuits are commonly used in british wiring with socket outlets taking fused plugs to bs 1363 because the breaker rating is much higher than that of any.
As you can see it eliminates the need to wire a socket all the way back to the a consumer unit but the nearest ring main socket is used instead.
The earthing conductor is uninsulated since it is not intended to have any voltage difference from surrounding earthed articles.
The cable size is important it has to be either 2 5sq mm or 4 0sq mm twin core and earth these are rated in free air at 24amps or 32amps respectively.
The main purpose of a spur is adding an extra socket on to an existing ring main circuit.
The ring starts at the consumer unit also known as fuse box distribution board or breaker box visits each socket in turn and then returns to the consumer unit.
Its simplicity makes it a great arrangement for that use.
Sizes of 1 or 1 5 mm 2 are typically used for 6 or 10 ampere lighting circuits and 2 5 mm 2 for 20 ampere radial or 32 ampere ring socket circuits.
In this video i show how to wire a spur socket to a ring final circuit using 2 methods 1.
The ring is fed from a fuse or circuit breaker in the consumer unit.
The diagrammes below show how you can break into a ring main with junction boxes to.
These rules can be found in our ring main project.