How many spur off ring main

Trying to connect two or more is not only very difficult due to the number of wires involved, it can also result in an abnormally high load at that point in the ring.

The number of spurs on the ring must not exceed the number of other socket outlets. If for some reason you need a large number of spurs, it is time to replace the whole circuit rather than keep adding to it.

Ring Circuits - Adding a socket outlet 1 There are three ways of adding a socket outlet to a ring circuit. Spur from existing socket outlet A single cable is added from the new socket, and connects to an existing socket on the ring.

Socket outlet wiring The spur socket only has a single cable, with the connections to Live, Neutral and Earth. Spur Limitations Only one socket outlet can be connected to a spur.

If it is a 20A radial cct you can do what you like. One rule of thumb is to assign a maximum draw of 1. The IET Wiring Regulations BS permit an unlimited number of 13A socket outlets at any point unfused single or double, or any number fused to be installed on a ring circuit , provided that the floor area served does not exceed m 2. Break the circuit at the socket in question. Check for continuity between the two line conductors. If continuity is present, it's likely to be on the ring could be on a figure of 8 loop.

To confirm, remove the line conductors at the board. Under the new , revised regulations, electrical work undertaken in kitchens such as adding a new socket or work outdoors such as installing a new security light will no longer be notifiable unless a new circuit is required.

This will mean less work has to be notified by electricians. Re: Adding wall lights - run from an existing socket? You can wire an external socket in the same manner as a normal spur, by running the cable from a socket or junction box on a main ring circuit via a switched connection unit and mounting the socket on an external wall.

Ensure your circuit has RCD protection, and that you use appropriate weatherproof outdoor fittings. The cable itself can be up to 60 meters long if it is protected by a cartridge fuse and 50 meters long if protected by an MCB. There is no limit to the number of sockets you can have on a ring main but there is a limit to the number of spurs you can have from those sockets or from the wiring between them.

The maximum length allowed for an unfused spur is 3m. The general rule of thumb, is that you can have an unfused spur at each socket, and one at the CU.

So basically a spur of a spur is never permitted, even if its fused. I'll have to just stick in a juntion box in the ring cables under floorboard and get a fused spur off that. Put a 13amp unswitched spur adjacent to the socket, then you can run whatever you like within reason from the outgoing or load side of that. A fused spur is an electrical supply accessory that incorporates a fuse. This fuse , with a lower rating than the fuse for a ring man, allows an electrical supply using one feed cable to a socket to be taken off a ring main.

The number of points allowed off each type spur differ…. Non-fused spur can only have one twin socket or one fixed appliance and a fused spur can have as many sockets as you require but care should be taken to ensure that the total load does not exceed the 13A fuse within the switched or unswitched-fused connection unit.

This 13A max load may be okay in a conservatory but not in the kitchen.