Switched fused spur off ring main for electric fire and LED strip

[combilau]

It's good practice to have separate rate fused spur for each and instructions may state that, but there's no safety risk in using one spur? Why can't you have two separate spurs?

 

[Pete999]

Why not?

It's a bit of a rough job to take two outputs from one spur IMHO

 

[davesparks]

I don't agree, obviously it's unacceptable to take two flexes out through the flex grip, but other than that I see no problem.

 

[Pete999]

I don't agree with you Dave, 1 spur for 1 item, if you feel that your way is OK then that's your prerogative, but you wouldn't catch me doing it, a right old butchers job IMHO, but hey ho I not arguing any more that's not the way to do things the FCUs aren't designed for that scenario 2 FCUs is the right way

 

[camerabloke]

Agree with Pete. Spur for each flex. 1 spur 2 flexes is yeee hah IMO

 

[Darkwood]

If they both enter the flex grip at the front of the spur then no as its designed to grip 1 flex .... if through back then as long as the multi stranded cores are suitably crimped and can fit into the terminal without issues then not poor standards or workmanship its is completely ok as long as fusing and S/C protection meet requirements.

Explain to me why if you disagree - and give good backup to the argument not a personel opinion.

 

[Pete999]

Right so the OP is suggesting that he wants to fit 2 outputs to a fused spur, correct? to me that's like connecting 2 different circuits to a cb in a consumers unit. So he has 2 outputs protected by what is after all a plug top fuse, you wouldn't connect 2 leads to a 13a plugtop would you? becaus in effect that's exactly what he is proposing is it not?

In the OPs way of doing things the system will work OK until the fuse ruptures for whatever reason, how will he know which item, in this case an electric fire and a strip of LEDs has caused the fuse to blow, that's my opinion and I stick by it.

 

[Darkwood]

Right so the OP is suggesting that he wants to fit 2 outputs to a fused spur, correct? to me that's like connecting 2 different circuits to a cb in a consumers unit. So he has 2 outputs protected by what is after all a plug top fuse, you wouldn't connect 2 leads to a 13a plugtop would you? becaus in effect that's exactly what he is proposing is it not?

In the OPs way of doing things the system will work OK until the fuse ruptures for whatever reason, how will he know which item, in this case an electric fire and a strip of LEDs has caused the fuse to blow, that's my opinion and I stick by it.

You can run 2 socket radials out of a 20amp MCB and be in compliance .

I expressed the cable grip is only suitable for 1 flex so not in compliance and would only comply if alternative secured/gripped entry was made.

If the terminals of the load side can easily take the 2 cores without compromising their ability to clamp both cables suitably then you can run more than 1 circuit off one fused output, the only regulation that would come into the equation would be any major inconvenience caused by a fault on 1 load would take the power out to the other and as this isn't your BT Exchange House then inconvenience is minimal and this set-up already exist in a split board design with multiple circuits on 1 rcd.

Just because you may never have entertained this method does not mean its in anyway wrong... its a set-up used often in control systems and really all that has occured here is the common connection point has been brought more upstream then commonly found in domestic set-ups.

Running a lighting circuit of a 6amp breaker then adding a E/M light and wiring it back to the same mcb is another commonly used example. The cables are still protected as required and can save time and materials in some set-ups.

 

[Pete999]

This isn't a control circuit is it? its 2 different items of equipment albeit small items, your scenario about adding an EM to an existing lighting circuit I agree with, but come on 1 spur for each item the spur is feeding. JI can't find any reference to this other than appendix 15 so I can't prove to you that it's wrong, just my gut feeling

 

[Darkwood]

This isn't a control circuit is it? its 2 different items of equipment albeit small items, your scenario about adding an EM to an existing lighting circuit I agree with, but come on 1 spur for each item the spur is feeding. JI can't find any reference to this other than appendix 15 so I can't prove to you that it's wrong, just my gut feeling

Yes agree it not control circuit but the principle theory and regulations covering such are cast from the same mould.. hence you will not find it. I understand why you don't see this is ok .. Ive had many a confliction over my years where ive used my personal opinion ahead of actual regulation and sometimes takes a bit to re-adjust the way I viewed certain scenario's.... Im not trying to get one up on you here im just expressing that in the OP's set-up if each cable was brought in separately and secured properly as well as termination been sound then it would comply and not be in any way in breach of regulation.

Having said this if designing the install from scratch and providing the points for the fire and LED set up then yes you would design a separate outlet for each as this would be classed as poor design not to but as to make use of an existing set-up it complies fully if the points Ive raised are met. As I said earlier if you don't agree then provide the relevant regulation.

 

[Pete999]

Yes agree it not control circuit but the principle theory and regulations covering such are cast from the same mould.. hence you will not find it. I understand why you don't see this is ok .. Ive had many a confliction over my years where ive used my personal opinion ahead of actual regulation and sometimes takes a bit to re-adjust the way I viewed certain scenario's.... Im not trying to get one up on you here im just expressing that in the OP's set-up if each cable was brought in separately and secured properly as well as termination been sound then it would comply and not be in any way in breach of regulation.

Having said this if designing the install from scratch and providing the points for the fire and LED set up then yes you would design a separate outlet for each as this would be classed as poor design not to but as to make use of an existing set-up it complies fully if the points Ive raised are met. As I said earlier if you don't agree then provide the relevant regulation.

I can#t provide you with any evidence, and don't worry about one upmanship, a healthy debate is just right, but to add, if FSUs were meant to have two loads they would make them with two holes, or make twin FSUs, now there's a thought.

 

[Darkwood]

I can#t provide you with any evidence, and don't worry about one upmanship, a healthy debate is just right, but to add, if FSUs were meant to have two loads they would make them with two holes, or make twin FSUs, now there's a thought.

Your scraping for an angle here - yes the unit itself is designed for 1 flex entry I agree 100% this is if you use their flex entry point .... but if your flexes were already in the backbox and secured by other means then you can disregard this part of their design as you have made an alternative solution.

Consider a flex from a spur 3amp fitted runs to an adaptable box out of this box you wire 4 GU10 fittings and a 4" fan to run at the same time...exactly the same thing but you have just made the joint elsewhere, forget the provided flex outlet part of the spur here we said it wouldn't comply if done as such its about having multiple loads of 1 FSU which is not bad practice if you have considered the loading, flex size and cable termination.

 

[Pete999]

Your scraping for an angle here - yes the unit itself is designed for 1 flex entry I agree 100% this is if you use their flex entry point .... but if your flexes were already in the backbox and secured by other means then you can disregard this part of their design as you have made an alternative solution.

Consider a flex from a spur 3amp fitted runs to an adaptable box out of this box you wire 4 GU10 fittings and a 4" fan to run at the same time...exactly the same thing but you have just made the joint elsewhere, forget the provided flex outlet part of the spur here we said it wouldn't comply if done as such its about having multiple loads of 1 FSU which is not bad practice if you have considered the loading, flex size and cable termination.

Call it a draw? you can't provide prove it's OK and I can't prove it's wrong

 

[davesparks]

In this particular situation the two outgoing cables are feeding a fire effect and an LED light in the fireplace.
So they are clearly intended to operate together as a single larger unit.

And two outgoing cables connected to one MCB is not two circuits, it is multiple branches of the same circuit.