How long can a spur off a ring main be?

Section 7.2. 2 of the OSG says 'as a rule of thumb for rings, unfused spur lengths should not exceed 1/8 the cable length from the spur to the furthest point of the ring'.

How far can you run a spur socket?

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.

How long can a spur cable be?

The unfused spur should supply just one single or one double (twin) socket outlet. It should be wired in 2.5mm2 P.V.C./P.V.C. T&E cable. There is no limit to the length of a spur, but Voltage drop considerations should be taken into account.

Can I run a ring main off a spur?

A spur can be connected to an existing socket, on either a ring main or a radial circuit, providing that socket does not already have a spur. That is only one spur per socket is allowed and the number of spurs must not exceed the number of sockets.

How many Spurs can you run off a ring main?

The rules for spurring off ring circuits are you are allowed ONE unfused spur to a socket (single or double) or ONE fused spur to as many sockets as you wish. You can't have both on the same point.

How to wire a spur socket to ring circuit. Add a spur socket to ring main.

Is it OK to spur off a spur?

The reason for not running two spurs from the same spur "point" is that it can lead to possible overloads in that one leg of the final can become unbalanced and exceed the max.

What is the maximum length of a ring main?

A good rule of thumb for ring finals wired in 2.5mm is that the total length of cable used should preferably not exceed 100m. In certain circumstances a larger total cable length may be admissible, but such circumstances need careful consideration.

Can you spur off a ring main in 1.5 mm?

no because you will have a 32 amp mcb protecting a 1.5mm2 cable.

Can I extend ring main to shed?

It can be done, and probably quite a bit more than 13A, but how much more is not clear. For a 35m long cable run outside, 4mm sq would be good for up to a 30A supply.

Can you spur off a ring main with a junction box?

A spur comes off the ring circuit via a junction box, or more usually via an existing socket - which ever is easier. See also Adding a spur to a ring circuit from a socket. To install a spur from a junction box, you require a 30amp junction box. Locate the cable of the ring main as close to the new socket as possible.

How long can a cable be on a fused spur?

It should be wired in 2.5mm2 P.V.C./P.V.C. T&E cable. There is no limit to the length of a spur, but Voltage drop considerations should be taken into account. It is not recommended that large loads like immersion heaters, large space heaters or similar loads be connected to the ring final circuit.

How much load can you put on a spur?

The maximum load you can run from a spur is 13A (Approx 3kW). If the sockets are fed from a fused connection unit (and fused at 13A) then the number of sockets supplied could in theory be as many as you want - providing that the total load of what ever you connect/use simultaneously doesn't exceed 13A.

Can I add more sockets to a ring main?

Rather than adding a spur to a ring main to provide an additional socket outlet, it may be advantageous to extend the ring.

Is it OK to spur off a socket?

The easiest way of connecting into a ring circuit is to run a spur cable from the terminals of an existing socket – but you can't connect it to any socket. The IEE Wiring Regulations are very specific about this. You mustn't run a spur from a socket that's already on a spur, or that already supplies a spur.

How many sockets can I run off 1 socket?

you can have maximum one double socket as a normal spur but if you are going from socket to FCU fused at 13 amp from there you can add as many sockets as you wish as all the sockets and cable will be protected by the fuse so no chance of overloading the cable the fuse will blow first.

Can I do electrical work myself?

Remember that any DIY electrical work carried out by an unregistered person must be tested and certified by a competent electrician, to ensure the safety of the wiring in your home.

Can you put a 20 amp double pole switch on a ring main?

Not a Problem as long as its fused and the fuse/switch is accessible, just the same as a socket spured off the ring using a 20A JB.

Is it illegal to do electrical work without a license UK?

A 'non-qualified' person can still carry out notifiable electrical work as long as Building Control are informed – but if you fail to do this and the work is found to be unsafe, it can lead to a hefty fine.

Can you mix 1mm and 1.5 mm cable?

IET Forums - Mixing cable sizes. So it's ok even if I have wired half of the circuit in 1.5 and then do the rest in 1mm. Yes, mixed cable sizes are fine provided that the smallest cable is compliant for the size and type of OCPD. AND that the voltage drop for the entire circuit is within acceptable limits.

Can I use 2.5 mm cable for sockets?

2.5mm is commonly used for behind sockets, while 1-1.5mm is most often used for lights (depending on how many lights you have in a circuit).

Can you put a double socket on a spur?

3 Answers from MyBuilder Electricians

A non-fused spur can only feed 1 double or single socket outlet or one permanently connected item of electrical equipment.

What is the maximum length for 2.5 mm radial circuit?

20 amp Design current for circuit Ib with 2.5 mm will give a volt drop of 11.5 volt at 32.35 meters, allowing for Correction factor Ct 0.9876.

How many 13 amp sockets can a ring main have?

The IET Wiring Regulations (BS 7671) 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 100 m².

How many amps can a 2.5 mm ring main take?

Given 2.5mm twin and earth clipped direct is 27 amps, times two for parallel is 54 amps for a clipped direct, ring.