2 external lighting circuits fed through 1 SWA cable

[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.