2 spurs coming from the same socket - NOT a spur from a spur!

HappyHippyDad · Oct 7, 2013

Hello all..

I have recently added a spur for a customer and it got me thinking again about how many spurs could I actually take from the same socket!

The only socket I could use to take the spur from was on the ring and was already feeding a spur. Now I could have extended the ring but after a small amount of investigation I found that the existing spur was to a single socket hidden behind kitchen cupboards and never used so I disconnected and then fitted my spur.

It did make me think what was wrong with adding 2 spurs to the same socket though. The new socket was a crabtree and could easily accomadate 4 2.5mm conductors.

A double socket that is feeding a double socket spur has the (unlikely) potential to take 26A from the spur plus another 26A from whatever is plugged into it (therfore a maximum of 32A could flow through that one socket). By adding another spur to the socket the maximum it could take is not changed (still 32A).

I think the answer is that although possible its not a good idea to push the limit of a socket and by adding another spur I am pushing it closer to the limit of 32A more frequently which would be bad practice and unecessary as you can just extend the ring, but I'm thinking about it and need answers from the experienced chaps as otherwise I shall become frustrated!!!!

Aindowsimon · Oct 7, 2013

happyhippydad said:
A double socket that is feeding a double socket spur has the (unlikely) potential to take 26A from the spur plus another 26A from whatever is plugged into it (therfore a maximum of 32A could flow through that one socket). By adding another spur to the socket the maximum it could take is not changed (still 32A).

!!!!

I might be misunderstanding this ?

Des 56 · Oct 7, 2013

Aindowsimon said:
I was quoting OP

Understood

[ElectriciansForums.net] 2 spurs coming from the same socket - NOT a spur from a spur!

I was only making available some information I had read

gazj82 · Oct 13, 2013

I changed a socket last week in a guys kitchen. It had three spurs off the ring in it! Five 2.5's do fit in a Crabtree socket, but by god did I swear! They all lunged out at me as I took the old socket off!

Lucien Nunes · Oct 13, 2013

They might physically fit, but can you trust the terminal to make secure contact to all conductors at the same time? I can think of situations with four or five cables in one hole, three were clamped but the others fell out. Not an ideal setup, you must have put in some effort to get it back together as I can imagine the original workmanship not being of the best.

gazj82 · Oct 13, 2013

It took some doing, each conductor got a good tug before the socket got screwed back.

electrician4u · Oct 16, 2013

happyhippydad said:
Hello all..

I have recently added a spur for a customer and it got me thinking again about how many spurs could I actually take from the same socket!

The only socket I could use to take the spur from was on the ring and was already feeding a spur. Now I could have extended the ring but after a small amount of investigation I found that the existing spur was to a single socket hidden behind kitchen cupboards and never used so I disconnected and then fitted my spur.

It did make me think what was wrong with adding 2 spurs to the same socket though. The new socket was a crabtree and could easily accomadate 4 2.5mm conductors.

A double socket that is feeding a double socket spur has the (unlikely) potential to take 26A from the spur plus another 26A from whatever is plugged into it (therfore a maximum of 32A could flow through that one socket). By adding another spur to the socket the maximum it could take is not changed (still 32A).

I think the answer is that although possible its not a good idea to push the limit of a socket and by adding another spur I am pushing it closer to the limit of 32A more frequently which would be bad practice and unecessary as you can just extend the ring, but I'm thinking about it and need answers from the experienced chaps as otherwise I shall become frustrated!!!!

when did 26+26 start equalling 32? it's 52

markc123 · Oct 16, 2013

electrician4u said:
when did 26+26 start equalling 32? it's 52

Edit.

Des 56 · Oct 16, 2013

electrician4u said:
when did 26+26 start equalling 32? it's 52

Yes indeed, 52 is what I made it ,mind you the double digit adding was a bit taxing for me

I think he had in mind 32 amp circuit max rating

markc123 · Oct 16, 2013

Mis-read the OP....can see how you've got the 52 now.

I just presumed in my brain the 32A rating.

Not to worry ladies and gents.

electrician4u · Oct 17, 2013

A 32A mcb doesn't act as a current limiting device! and btw, 52A would take about 10 minutes to trip a B type mcb and likely won't trip at all until about 47A being drawn, so the Regs say anyway.
don't underestimate the general publics' ability to abuse sockets. was called out to an office some time ago as they said their sockets were tripping to find a fan heater connected next to everyone's desk.they had 8 2kW heaters connected drawing 66A and the mcb still hung on for a few minutes after re-setting! in the last Regs you could spur off a spur but that's been changed obviously.

DPG · Oct 17, 2013

electrician4u said:
A 32A mcb doesn't act as a current limiting device! and btw, 52A would take about 10 minutes to trip a B type mcb and likely won't trip at all until about 47A being drawn, so the Regs say anyway.
don't underestimate the general publics' ability to abuse sockets. was called out to an office some time ago as they said their sockets were tripping to find a fan heater connected next to everyone's desk.they had 8 2kW heaters connected drawing 66A and the mcb still hung on for a few minutes after re-setting! in the last Regs you could spur off a spur but that's been changed obviously.

You could spur off a spur in the last regs ??? Daz

Deleted member 9648 · Oct 17, 2013

electrician4u said:
A 32A mcb doesn't act as a current limiting device! and btw, 52A would take about 10 minutes to trip a B type mcb and likely won't trip at all until about 47A being drawn, so the Regs say anyway.
don't underestimate the general publics' ability to abuse sockets. was called out to an office some time ago as they said their sockets were tripping to find a fan heater connected next to everyone's desk.they had 8 2kW heaters connected drawing 66A and the mcb still hung on for a few minutes after re-setting! in the last Regs you could spur off a spur but that's been changed obviously.

DPG said:
You could spur off a spur in the last regs ??? Daz

maybe the last regs book he possessed was the 13th?

markc123 · Oct 17, 2013

Haha, maybe wirepuller.

That's a interesting question to be fair. Whats the oldest copy of the regs anyone holds? Or do you just bin them?

I've got a shyte load of books in the attic...im a hoarder when it comes to electrical information and publications.

Deleted member 9648 · Oct 17, 2013

Started with the 14th and always regretted binning it,would be an interesting read now.

(note to self...GET OUT MORE)

Golden_Boy · Oct 17, 2013

As there is no MINIMUM distance that sockets can be spaced on a rfc.then in practice you could have 2 literally next to one another and have one spur from each of them. 3 or 4 inches of cable in between. Satisfies the regs but in practice is exactly the same as having 2 spurs from one socket, Thinking about it it is worse as there are now 8 outlets available...

2 spurs coming from the same socket - NOT a spur from a spur!

HappyHippyDad

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Aindowsimon

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Des 56

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gazj82

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Lucien Nunes

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gazj82

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electrician4u

markc123

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Des 56

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markc123

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electrician4u

DPG

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Deleted member 9648

markc123

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Deleted member 9648

Golden_Boy

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