2 external lighting circuits fed through 1 SWA cable

[cprfenom]

Evening,

Although I cannot see a specific regulation can anyone come up with a reason why someone could not run 2 line and 2 neutrals with both circuits fed from the steel wire?

To verify this would feed 2 number lighting circuits down one path, but

I.e 1No 5 core swa.

From a cost point of view this seems dumb, but the emergency lighting part also bothers me, not to mention testing.

 

[SparkyChick]

So, lets clarify... you want to run 2 circuits in a 4 core SWA using the armour as the CPC.

What's 'the emergency lighting part'? Why does testing worry you?

 

[Pete999]

Can you provide more information, a more detailed explanation of what is intended, it may be clear to you, but to someone coming in cold, it seems a rushed description, a diafram may help.

 

[cprfenom]

I personally don't want to just from an installation point of view, but lets see if I can walk through what is being discussed.

2 outside light circuits, but for ease of use I will say 20 lights.
10 will be non emergency and 10 will be emergency.

One 5 core swa with 2 cores being neutrals, 2 being line and one being and emergency fed from a powerpack.

 

[westward10]

It will be fine you can contain multiple circuits in a multicore cable providing the insulation is rated for the highest voltage present. Not sure what the power pack bit is, are these not self contained emergency lights.

 

[cprfenom]

I would have preferred to have self contained ems, but as these will be bollards the client would prefer to have a battery pack local to the DB. So in effect a central battery system?

 

[Pete999]

I personally don't want to just from an installation point of view, but lets see if I can walk through what is being discussed.

2 outside light circuits, but for ease of use I will say 20 lights.
10 will be non emergency and 10 will be emergency.

One 5 core swa with 2 cores being neutrals, 2 being line and one being and emergency fed from a powerpack.

You don't want to give any more information than what you have already, why is that? the more information the more help you will be able to get from the forum, keeping information from the forum is disturbing in my opinion, don't know how others feel?

 

[Wilko]

Just thinking out loud - do the emergency lights require a higher fire rated cable than the swa?

 

[cprfenom]

Genuinely I dont have anymore information. I am in the process of putting together what the client and our estimator were talking about. Personally I would just have 2 circuits with internal battery packs for the emergency bollards.

To me having 2 circuits, but only some being emergency off of a central battery through one cable is asking for crap

 

[Pete999]

Genuinely I dont have anymore information. I am in the process of putting together what the client and our estimator were talking about. Personally I would just have 2 circuits with internal battery packs for the emergency bollards.

To me having 2 circuits, but only some being emergency off of a central battery through one cable is asking for crap

OK appreciate your concerns Mate, no offence meant, just wondered why. the reluctance

 

[Pete999]

Genuinely I dont have anymore information. I am in the process of putting together what the client and our estimator were talking about. Personally I would just have 2 circuits with internal battery packs for the emergency bollards.

To me having 2 circuits, but only some being emergency off of a central battery through one cable is asking for crap

Yes but wouldn't the EM lights require a permanent live feed? Ah I see a central battery pack that explains your concern's, not sure of the answer I have no experience.

 

[westward10]

As the battery unit is remote this would fall under the requirements for a central battery system and hence any cabling must have an inherently high resistance to the effects of fire. Do you have a copy of BS5266:1.
Surely you would need a six core cable.

 

[westward10]

If it is a central system you will not be able to use the same cable, segregation will be required.

 

[Toneyz]

Are you saying there are two lighting circuits for the bollards?
One of the circuits will have EM. back up?

 

[Toneyz]

Genuinely I dont have anymore information. I am in the process of putting together what the client and our estimator were talking about. Personally I would just have 2 circuits with internal battery packs for the emergency bollards.

To me having 2 circuits, but only some being emergency off of a central battery through one cable is asking for crap

Is there anyone designing this to comply with the relevant B.S.
For what you have described so far seems a complicated setup yet alone termination inside the bollards. I know ASD does an emergency bollard and other manufacturers do as well probably now. It, therefore, must be simpler to have a five core SWA.

 

[cprfenom]

Yes. That is what will be

 

[Pete999]

If it is a central system you will not be able to use the same cable, segregation will be required.

Would that statement be untrue if all the conductors are rated at the highest voltage? only asking.

 

[westward10]

Would that statement be untrue if all the conductors are rated at the highest voltage? only asking.

No for central systems segregation must be applied.
Part of Reg 8.2.6, BS5266:1. Where multi-core cable is used for the emergency lighting, none of the conductors should be used for any other circuit.

 

[westward10]

You will have to use separate cables, the cable for the emergency lighting you could use FP600. Are these bollards forming part of an escape route.

 

[Pete999]

No for central systems segregation cheers thanks for that Westymust be applied.
Part of Reg 8.2.6, BS5266:1. Where multi-core cable is used for the emergency lighting, none of the conductors should be used for any other circuit.

 

[Pete999]

Cheese thanks Westy

 

[cprfenom]

They are specifically a walk way through the grounds of a private school. They are opting for EM lighting, but there is no specific requirement for them.

Thank you Westy, that has cleared some details up.

 

[Toneyz]

If you are using four core SWA or five if one circuit has P/L how are you going to terminate at each bollard? Having thought about it I would run two SWA's one for each circuit then safe isolation is not a problem either.

 

[westward10]

He cannot run them in one cable anyhow, but I agree segregating them within the bollard will be an issue.

 

[Toneyz]

He cannot run them in one cable anyhow

I take it that this applies if he is still going with the emergency power pack remote. I think self-contained is a better option.

 

[westward10]

Self contained would be a better option.

 

[cprfenom]

I personally agree that self contained is a better option.

For me I wanted clarification in regards to the idea as I am not the one who is coming up with the idea.

 

[GBDamo]

I personally agree that self contained is a better option.

For me I wanted clarification in regards to the idea as I am not the one who is coming up with the idea.

Is the person coming up with the ideas aware of all the options?

I work with some "A little knowledge is a dangerous thing" types and often getting the job done correctly is an excersise in planting the seeds of the correct way in their head and letting them come up with the correct way.

As Westy said a 'maintained' self contained EM bollard is the way to go. This way you can get away with a three core and earth SWA.

 

[Nigel]

There is so much wrong here.

Firstly if you are using a CBS then this will be either 24/50/110v. If the bollards are 230v how do you propose to manage this?

Secondly as has been mentioned a CBS wiring needs to be segregated which clearly cannot be achieved if they are the same cable.

Thirdly as the installer you will need to agree the design. The defence of ‘it was designed by someone else’ does not wash with emergency lighting or fire alarm systems. The installer is equally as responsible.

If the client is insistant on a central system then they need to look at installing a static inverter system whichnis then 230v. Segregation will still apply and the cable will need to be fire resistant to whatever the FRA requires. Generally FP600 would be fine in your scenario.

A central battery system will need much more lighting also to achieve the required lighting levels which, if an escape route in a school will likely need to be 3 Lux along the centre line of the escape route. A static inverter will be an increased up front cost but cheaper in the long run as single point emergency lights need there batteries changed every four years. There will be no EBLF drop either.

There will need to be daily checks on a static inverter or battery system.

 

[cprfenom]

You will be pleased to know. I have persuaded the client and our estimator that stand alone emergency fittings is a better a more viable option. Case Closed.