Fused 4 ways good, unfused 4 ways bad?

[Chris Holmes]

At work the Fire Officer is having a clampdown on Unfused 4 Way Mains Blocks/Leads.

I presume this is following advice either from his "industry" or from facilities (a separate company who charge us loadsamoney for anything they do)

Any ideas what the rationale might be behind this?

I can think of a few....

Perhaps they feel that in general fused 4 ways are better quality then unfused.

They feel that having a fuse at the outlet end of a 4 way on a long cable (most of ours are 2 metres) might blow / blow faster than just having them fused in the plug.

They feel that supplying us with a load of good quality (expensive) 4 ways at a premium, is a major contribution to their new greenhouse!

Any ideas as to whether these unfused 4 ways are generally regarded with suspiscion (and why)?

TIA

Chris

[Mike Barnes]

Chris Holmes :

Ask him/her for their evidence.

[meow2222]

If they're on a lead with a fused plug, there is no safety difference wheth er the socket is fused or not.

If they're wired direct to the ring circuit, there are a few problems. Thei r max total rating is 13A total, which is easily exceeded with 4 sockets. A quad socket on a spur can overload the spur cable. The plastic is not nece ssarily able to contain a minor fire.

Most things are driven by profit - at your expense

NT

[Andrew Gabriel]

I would guess that a 4-way socket is not explicitly covered by BS1363, and therefore it needs a fuse to be legal (same as for 3-way adapters and 3-way socket outlets). Double sockets and 2-way adapters don't require a fuse, because they're explicitly covered by BS1363.

If this is the case, then 4-way sockets without fuses haven't been manufactured to BS1363 (which makes them illegal to manufacture or import), and there will be other aspects of them which don't conform, and they haven't been properly tested. That's a good enough reason not to use them, even though that fuse is redundant when made up into an extention lead with a fused plug on it, _if_ the plug and fuse conform to BS1363 and BS1362. There have been cases of this in the past where there was also something wrong with the mains flexes used by the socket blocks.

I don't have BS1363 though (I did have some parts of it once, but I can't find them now).

[Dave Plowman (News)]

He's simply got a bee in his bonnet. Ask him what electrical qualifications he has to come to this conclusion.

[Dave Plowman (News)]

I'm assuming it is a four way outlet on a flex plugged into a 13 amp socket, so protected by the fuse in the plug?

Any rational which said the outlet on what is essentially an extension lead would surely apply regardless of the number of ways? And I've never seen a single flex outlet with a fuse - although they are common enough on

4+ way ones.

[Andrew Gabriel]

Not sure if you didn't read what I wrote, or my message didn't come across, but at the most basic level, if the socket doesn't conform to BS1363, what makes you think the lead, plug, and 13A fuse (if it has one) which you seem to be relying on instead conform?

[Brian Gaff]

I'd not say fused ones are any better made an unfused ones, though the unfused are probably now quite old as I've not seen them on sale for some time. The way the bent bits of metal and rod only connect really well when you shove plugs in seem to be very poor to me and most seem to be made this way.

Brian

[John Rumm]

Unfused ones (i.e. ones with no additional fuse in the socket itself) are commonly and widely available. They probably make up the bulk of the ones on sale I would estimate.

Indeed - they are not quality items.

[Dave Plowman (News)]

It seemed to be a 'what if' post.

Causally glancing at some various 4 way extension leads hanging in this workshop - no idea where they came from - finds them all marked BS 1363/A

[Dave Liquorice]

Well you wouldn't would you. B-)

Bought several 4 way, unfused at the socket, extension leads last year. Looked at one earlier marked BS1363/A (might have been B). It also states it is non-rewireable and a maximum load of 10A. I wonder if the plug top fuse is 10A...

[Mike Tomlinson]

En el artículo , John Rumm escribió:

Time for a repost of this :-)

Kwality...

[newshound]

Yes, but it has probably failed *safe*, hasn't it, even if it wasn't protected by an RCD. The only real risk is if it was located where it was insulated by flammable material.

[Dave Liquorice]

But all the contacts for the plugs into that socket strip all look fine. What has let out lots of magic black smoke are a couple of electrical components, probably MOVs used as "surge arrestors".

[Mike Tomlinson]

En el artículo , Dave Liquorice escribió:

The contacts are made up of one long strip of metal which is very thin and flimsy. I'd be unhappy about pulling 13A through that.

[Dave Liquorice]

How wide and thick? 4 mm x 0.5mm = 2 mm^2 ample for 13 A.

[Andy Burns]

But they're brass rather than copper, so you'd need 2x to 4x the csa.

[Dave Liquorice]

1 mm^2 copper T&E is rated at 14 A (thought it was a tad higher) so 2 mm^2 of brass is a similar ball park.