OK to run an FCU off a spurred socket?

[ARWadsworth]

The fuse is after the 2.5 T&E connections. It protects sweet FA in hard wiring terms.

Adam

[dennis]

It protects against overloads. The main fuse should protect against a serious fault like a short. Or that is the theory used for ring mains.

[Dave Plowman (News)]

As would be drawing 13 amps off every socket on a ring. The system relies on probabilities - just where in a domestic situation would you want to draw two lots of continuous 13amps from a double socket?

The most likely would be in a kitchen - but then pretty well all appliances there don't draw a high current for very long.

[ARWadsworth]

Name that reg.

Adam

[Dave Plowman (News)]

Some have always been full of 'what ifs' about rings. But the fact remains that is by far the most satisfactory arrangement for domestic mains outlets - even more so than when first designed.

[John Rumm]

Hmmm, I have a feeling he made that up as well ;-)

[dennis]

Not so.. it would trip the circuit breaker. The twin socket could have two fan heaters plugged in and overload the feed cable without the fuse blowing.

Anywhere if the CH fails, a couple of fan heaters would be 26A.

[dennis]

Radial.

[Frank Erskine]

On Tue, 19 May 2009 22:14:39 +0100, "Dave Plowman" had this to say:

Probably not in a true domestic situation, but quite possible where a similar installation could very well be in use in, say, a church hall, and two kettles could be in fairly continuous use for a tea-party.

Granted, a domestic ring-main isn't entirely appropriate there, but I should imagine there's a lot of it about... :-)

[Dave Plowman (News)]

If you needed two fan heaters in a room wouldn't you put them either side of it?

But the probability of running them off one double socket is near zero in practice.

[Dave Plowman (News)]

Commercial installations are a very different matter. And a church hall used for this sort of thing would normally have an urn.

As I said' lots of 'ifs'. ;-)

[geoff]

In message , "Dave Plowman (News)" writes

Except in chateau dennis

[Frank Erskine]

On Tue, 19 May 2009 23:29:11 +0100, "Dave Plowman (News)" had this to say:

More tea, vicar?

[ARWadsworth]

A spur in 2.5 T&E feeding only one outlet (double socket included) is perfectly acceptable from a ring with a 30A fuse.

I frequently use them when doing a rewire where there is a socket that would involve a long silly run of cable. This is not down to the cost of the cable but to keep the actual length of the ring down to allowed sizes. I most commonly do this for things like a socket in a loft (TV booster etc).

Adam

[Dave Plowman (News)]

I'd run that off the lighting circuit since it's already there.

[dennis]

People putting a fan heater in the loft would be quite rare and they would have to plug a 4 way strip in first. I think all the lights should be connected via 13A plugs and sockets, then you can move them about easier and plug in things like X10 controllers, etc.

[ARWadsworth]

Tempting and very often used by me for later additions but not for rewires.

I will fit a 5 amp socket for a TV amp from the lighting circuit. But if the customer asks for a socket in the loft on a rewire then they get a socket in the loft from the ring and not one from a 6A supply.

Adam

[ARWadsworth]

And I think that Kylie Minouge would look nice sat on my knob. We can all dream and make stuff up.

Adam

[Dave Plowman (News)]

And correctly so. Wonder how many 13 amp sockets you've come across in a loft fed from the lighting circuit?

[ARWadsworth]

Quite a few. And not just in lofts!

Adam