Spurring of a spurred socket

[Welsh_sparky_21]

Is spurring off a sockets that’s already been spurred off a major no no?? It’s for a socket behind a wall mounted tv so not gony be a major load on the cable

 

[Pete999]

Is spurring off a sockets that’s already been spurred off a major no no?? It’s for a socket behind a wall mounted tv so not gony be a major load on the cable

It is unless you connect a FCU into the equation as per the Appendix 15

 

[telectrix]

as above^^. it's not compliant, but you won't get dragged away by the IET Gestapo and have your sidecutters surgically removed.

 

[radiohead]

While not technically compliant I can see no real problem with spurring a single socket from another single socket which itself is a spur. The reasoning being that the number of outlets on a spur is the same as a compliant twin socket fed as a spur from a ring. Any other scenario of more than one outlet from a spur would require being supplied through a 13a fused connection unit to avoid the possibility of overloading the spur conductors.
It is far better though to avoid spurs and feed all outlets by properly extending the ring.

 

[Dartlec]

as above^^. it's not compliant, but you won't get dragged away by the IET Gestapo and have your sidecutters surgically removed.

Speak for yourself - I live royally off the commission from reporting such naughtiness....

On a more serious note - The current use may be a TV - then the next person comes along and mounts two 3kW heaters on the wall. (Obviously the cable won't immediately burst into flames even in that case but it could certainly cause problems down the road)

The real reason not to do it IMO is that it's a PITA for trying to test and inspect visually when you think it's a ring...

If you're running a new cable from the socket, then add a FCU at the original socket.

It's a shame that none of the manufacturers produce a replacement two gang socket with one gang as a FCU - it would make this sort of situation easier. I assume you could do it with grid systems, but probably at quite a cost...

 

[ipf]

as above^^. it's not compliant, but you won't get dragged away by the IET Gestapo and have your sidecutters surgically removed.

Don't you mean his testiquipment?

 

[Dartlec]

While not technically compliant I can see no real problem with spurring a single socket from another single socket which itself is a spur. .

There is an argument for this, though that would assume that the cable is not derated at all during its run as 26A is in best circumstances. And I doubt anyone is going to do the calculations or written risk assessment to cover themselves in a court if something were to happen...

Most double sockets are rated at 20A I believe, not 26A, partly for this reason - And many of the cheap sockets would probably struggle with 20A from the state I've seen some of them when installed in kitchens.

I recently found a 2.5mm radial covering kitchen and downstairs which had been on a 32A MCB for at least 10 years. The cable passed IR testing perfectly - though some of the sockets had to be replaced for melty connections.

 

[ChrisElectrical88]

While not technically compliant I can see no real problem with spurring a single socket from another single socket which itself is a spur. The reasoning being that the number of outlets on a spur is the same as a compliant twin socket fed as a spur from a ring. Any other scenario of more than one outlet from a spur would require being supplied through a 13a fused connection unit to avoid the possibility of overloading the spur conductors.
It is far better though to avoid spurs and feed all outlets by properly extending the ring.

Technically not right
But your not going to put any cables or terminals under any sort of stress doing this. Still going to pull 26A Max.

 

[Pete999]

Don't you mean his testiquipment?

No his electrical qualifications
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Don't you mean his testiquipment?

Well you should be.
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There is an argument for this, though that would assume that the cable is not derated at all during its run as 26A is in best circumstances. And I doubt anyone is going to do the calculations or written risk assessment to cover themselves in a court if something were to happen...

Most double sockets are rated at 20A I believe, not 26A, partly for this reason - And many of the cheap sockets would probably struggle with 20A from the state I've seen some of them when installed in kitchens.

I recently found a 2.5mm radial covering kitchen and downstairs which had been on a 32A MCB for at least 10 years. The cable passed IR testing perfectly - though some of the sockets had to be replaced for melty connections.

Don't make it compliant though does it





















?

There is an argument for this, though that would assume that the cable is not derated at all during its run as 26A is in best circumstances. And I doubt anyone is going to do the calculations or written risk assessment to cover themselves in a court if something were to happen...

Most double sockets are rated at 20A I believe, not 26A, partly for this reason - And many of the cheap sockets would probably struggle with 20A from the state I've seen some of them when installed in kitchens.

I recently found a 2.5mm radial covering kitchen and downstairs which had been on a 32A MCB for at least 10 years. The cable passed IR testing perfectly - though some of the sockets had to be replaced for melty connections.

Don't make it compliant though does is it?

 

[Dartlec]

Technically not right
But your not going to put any cables or terminals under any sort of stress doing this. Still going to pull 26A Max.

Probably true - though I'm sure someone could find an unfused euro pin adapter and take rather more - not that unusual I'd suspect in a rental property.

That's why compliance is always the best option - then it's never your fault when the end user does something stupid....

 

[radiohead]

There is an argument for this, though that would assume that the cable is not derated at all during its run as 26A is in best circumstances. And I doubt anyone is going to do the calculations or written risk assessment to cover themselves in a court if something were to happen...

Most double sockets are rated at 20A I believe, not 26A, partly for this reason - And many of the cheap sockets would probably struggle with 20A from the state I've seen some of them when installed in kitchens.

I recently found a 2.5mm radial covering kitchen and downstairs which had been on a 32A MCB for at least 10 years. The cable passed IR testing perfectly - though some of the sockets had to be replaced for melty connections.

The point about double sockets being rated at 20a has been levelled against this before, but in practice no punter will take this into account when plugging appliances in. If they want to plug in 2x 3kw heaters they will plug them into whatever is there, be that a twin or two singles. The same applies to the rating of the cable, whether it is a twin spur or two singles it can still be subject to exactly the same load.
The point about testing being complicated by a single spur from another single spur is a valid one, but any competent electrician should be able to ascertain how this is wired and come to a conclusion that in practice there is no more hazard from two singles as one twin on a spur.
Why cant some people explain their disagreement when something is put forward rather than a silly red cross?
Actually I know why.

 

[ChrisElectrical88]

Probably true - though I'm sure someone could find an unfused euro pin adapter and take rather more - not that unusual I'd suspect in a rental property.

That's why compliance is always the best option - then it's never your fault when the end user does something stupid....

Yeah, I’m only saying in theory like we all are, would never install i that way ?

 

[littlespark]

The wiring regulations are there for a reason. A spur off a spur is non compliant. Simple as.

If this first spur was taken from a 16A radial circuit, then that's a different story.
(cough change the breaker cough)


Yes. I know... Very simplistic solution. I dont know how many points are on the circuit already.... might be all of downstairs with kettles and heaters and whatever else.

If its an easy enough job, FCU at the source of the spur, as suggested above. Then everything taken off is limited to 13A.

 

[radiohead]

The wiring regulations are there for a reason. A spur off a spur is non compliant. Simple as.

If this first spur was taken from a 16A radial circuit, then that's a different story.
(cough change the breaker cough)


Yes. I know... Very simplistic solution. I dont know how many points are on the circuit already.... might be all of downstairs with kettles and heaters and whatever else.

If its an easy enough job, FCU at the source of the spur, as suggested above. Then everything taken off is limited to 13A.

The wiring regulations are not statutory, and departures are permitted where it can be demonstrated that the resulting degree of safety is not less than that obtained by compliance.
Nobody can give a valid reason why a single socket spurred from another single socket itself wired from a spur is any less safe than a double outlet on a spur. There is no more chance of overloading the supply cable, or the outlets themselves, and it can be tested and verified in the same way as any other wiring.

 

[Ian1981]

Departures are permitted but there’s a difference between a departure and a non compliance

 

[Dartlec]

The wiring regulations are not statutory, and departures are permitted where it can be demonstrated that the resulting degree of safety is not less than that obtained by compliance.
Nobody can give a valid reason why a single socket spurred from another single socket itself wired from a spur is any less safe than a double outlet on a spur. There is no more chance of overloading the supply cable, or the outlets themselves, and it can be tested and verified in the same way as any other wiring.

I think if someone supplied a certificate for such work, noting the departure and attaching a risk assessment (even a simple one), then I wouldn't immediately consider it bad practise.

However, I wonder if there is more risk of maximum load being run on two single sockets, perhaps with multi gang extensions in each if they are the only sockets in the room - at which point you could run 14A through each without a fuse tripping. (Though these days there are fewer things outside of heating that get close to that of course)

Double socket designers clearly have decided that the risk of both outlets being run at maximum is low enough to justify their rating. In the case of single sockets the installer is becoming the designer and has to justify that risk.

If I were assessing the situation for continued use in an EICR I think I'd be working from the starting point of a C2 and looking whether there are reasons it should not be noted as such.

If it was in a bedroom with no heating and a heater or hairdryer might be plugged in I might judge it differently than if it was behind a TV as in this case and less likely to be used for anything else.

However, what would happen when the next owner comes along and decides to get that single socket replaced with a double by her handyman who isn't as careful as the original installer? Should the original installer be taking that possibility into account? I honestly don't know the answer to that... Would a judge consider him to have no responsibility if something were to occur?

The answer to the original question is clearly no it's not compliant. However it may well be safe in most circumstances, but possibly not all.

 

[radiohead]

"I think if someone supplied a certificate for such work, noting the departure and attaching a risk assessment (even a simple one), then I wouldn't immediately consider it bad practise.

However, I wonder if there is more risk of maximum load being run on two single sockets, perhaps with multi gang extensions in each if they are the only sockets in the room - at which point you could run 14A through each without a fuse tripping. (Though these days there are fewer things outside of heating that get close to that of course)"
Are you suggesting that an end user would think there is a difference between what he can plug into a single socket and a double socket?
It does not matter how many muti-gang extensions are run off a 13a outlet, they are protected against overload by a 13a fuse in the plug.

"Double socket designers clearly have decided that the risk of both outlets being run at maximum is low enough to justify their rating. In the case of single sockets the installer is becoming the designer and has to justify that risk."
Again, an end user will not differentiate between a single or double outlet, he sees a 13a socket and plugs whatever he wants into it

"If I were assessing the situation for continued use in an EICR I think I'd be working from the starting point of a C2 and looking whether there are reasons it should not be noted as such."
I disagree. I cannot see how a double outlet on a spur is safe and compliant but two single outlets are potentially dangerous. Illogical.

"If it was in a bedroom with no heating and a heater or hairdryer might be plugged in I might judge it differently than if it was behind a TV as in this case and less likely to be used for anything else."

"However, what would happen when the next owner comes along and decides to get that single socket replaced with a double by her handyman who isn't as careful as the original installer? Should the original installer be taking that possibility into account? I honestly don't know the answer to that... Would a judge consider him to have no responsibility if something were to occur?"
What if the handyman extends the ring in 1.0mm, what if he changes the OCPD for a 50a?
Those working with electrics in dwellings are required to be competent. We cannot be responsible for what happens to an installation after we have handed it over.
"The answer to the original question is clearly no it's not compliant. However it may well be safe in most circumstances, but possibly not all".
In which would it not be safe?

My answers in red

 

[Pete999]

Departures are permitted but there’s a difference between a departure and a non compliance

"I think if someone supplied a certificate for such work, noting the departure and attaching a risk assessment (even a simple one), then I wouldn't immediately consider it bad practise.

However, I wonder if there is more risk of maximum load being run on two single sockets, perhaps with multi gang extensions in each if they are the only sockets in the room - at which point you could run 14A through each without a fuse tripping. (Though these days there are fewer things outside of heating that get close to that of course)"
Are you suggesting that an end user would think there is a difference between what he can plug into a single socket and a double socket?
It does not matter how many muti-gang extensions are run off a 13a outlet, they are protected against overload by a 13a fuse in the plug.

"Double socket designers clearly have decided that the risk of both outlets being run at maximum is low enough to justify their rating. In the case of single sockets the installer is becoming the designer and has to justify that risk."
Again, an end user will not differentiate between a single or double outlet, he sees a 13a socket and plugs whatever he wants into it

"If I were assessing the situation for continued use in an EICR I think I'd be working from the starting point of a C2 and looking whether there are reasons it should not be noted as such."
I disagree. I cannot see how a double outlet on a spur is safe and compliant but two single outlets are potentially dangerous. Illogical.

"If it was in a bedroom with no heating and a heater or hairdryer might be plugged in I might judge it differently than if it was behind a TV as in this case and less likely to be used for anything else."

"However, what would happen when the next owner comes along and decides to get that single socket replaced with a double by her handyman who isn't as careful as the original installer? Should the original installer be taking that possibility into account? I honestly don't know the answer to that... Would a judge consider him to have no responsibility if something were to occur?"
What if the handyman extends the ring in 1.0mm, what if he changes the OCPD for a 50a?
Those working with electrics in dwellings are required to be competent. We cannot be responsible for what happens to an installation after we have handed it over.
"The answer to the original question is clearly no it's not compliant. However it may well be safe in most circumstances, but possibly not all".
In which would it not be safe?

My answers in red

Because a spur constitutes a single or a double outlet

 

[radiohead]

Because a spur constitutes a single or a double outlet

Only to those who behave like lemmings and are unable to actually apply some logic to whatever they are doing.
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Utterly predictable red cross Pete.
No valid argument.
No logic.
No explanation for a point of view.

I respect any differing argument if you can actually put one forward beyond... 'because it is, ok'?

 

[littlespark]

Before any other scouser chirps in, I will quote one of their favourite phrases....

"Eeeh... calm down, calm down!"


No point trying to argue the case... BS7671 says its non compliant, therefore we shouldn't be doing it, or advising that its safe to do so.
Non compliant, if this is indeed an RFC, wired in 2.5, off a 32A OCPD.

The ideal solution has been suggested, early on.. (13A FCU supplying the spur) Arguing over why it 'could' be done, or speculating why it shouldn't just in case an idiot comes along later...
These conversations have no doubt been discussed before any regs were published, and they've come up with "only one unfused spur from an RFC"