Preferred cable type and installation method

[atm84]

Just about to start the design on a refurbished school and looking for suggestions on cable type and installation method.

I've always been a fan of trunking and conduit with eitherT&E or singles on commercial installs due to robustness and quality but understand the cost implications and have recently come across many installation where twin and earth and basket has been used or even earthed sheathed cable has been used.

What are your favourite installation methods and cable types and why. Consider that you are the designer and its YOUR call.

 

[telectrix]

t/e in basket or tray. drops in conduit. most probably have to use LSF cable.

 

[trev]

Pyro, clipped direct.

 

[Paul.M]

School = Check with the local Clerk of Electrical Works before you begin. Get the full spec before you start and any designated computer sockets need to have a supplementary 4mm earth. EM lighting design needs to be perfect, so dose the cable support on exit routes (and everywhere else tbo). Socket and switch drops may need to be in galv, check with the Clerk before starting the job.

Have fun but do your homework with everyone that is involved.

 

[atm84]

Pyro, clipped direct.

Lovely, would that be sheathed or bare?

 

[atm84]

School = Check with the local Clerk of Electrical Works before you begin. Get the full spec before you start and any designated computer sockets need to have a supplementary 4mm earth. EM lighting design needs to be perfect, so dose the cable support on exit routes (and everywhere else tbo). Socket and switch drops may need to be in galv, check with the Clerk before starting the job.

Have fun but do your homework with everyone that is involved.

Can you elaborate why computers sockets NEED to have a supplementary 4mm Earth. It doesn't say that in BS 7671

 

[atm84]

School = Check with the local Clerk of Electrical Works before you begin. Get the full spec before you start and any designated computer sockets need to have a supplementary 4mm earth. EM lighting design needs to be perfect, so dose the cable support on exit routes (and everywhere else tbo). Socket and switch drops may need to be in galv, check with the Clerk before starting the job.

Have fun but do your homework with everyone that is involved.

Like I said imagine if its YOUR call.

 

[shanky887614]

Just about to start the design on a refurbished school and looking for suggestions on cable type and installation method.

I've always been a fan of trunking and conduit with eitherT&E or singles on commercial installs due to robustness and quality but understand the cost implications and have recently come across many installation where twin and earth and basket has been used or even earthed sheathed cable has been used.

What are your favourite installation methods and cable types and why. Consider that you are the designer and its YOUR call.

atm if your wiring a school let me ask you this.

would you have multiple 6" trunkings or basket?

basket off uni strut hangers is the standard way with trunking confined to plantroom or surface etc

you can get mounting plates do you can bush into the basket with your galv conduit as well for the drops

 

[Sintra]

Personally if it was my call it would be a complete galvanised trunking and conduit system for LV power with all wiring done in 6491B cable. Life safety systems on galvanised tray wired in enhanced FP200.

 

[tazz]

There should be a cable schedule submitted already, councils are usually clued up to what they require.
Most schools we work on are installed total in singles off trunking, with drops in gav tube. But this only tends to be on new builds or full refurb, when ceilings etc are down, to install containment.

 

[trev]

Lovely, would that be sheathed or bare?

Bare of course, I'd hire a team of Lithuanian cleaners to polish it till you could see your face in it too

 

[Knobhead]

Why do people take on jobs and then expect a free design service on here.

As has been said, the education authority will have a preferred installation method which if you deviate from will cost dearly.

I like Trev’s idea of Pyro.

 

[Richo77]

Trunking and conduit for power and lighting. Basket for data and fire alarm system

 

[davesparks]

basket off uni strut hangers is the standard way with trunking confined to plantroom or surface etc
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Are you sure about that? All new build school work, and bigger commercial for that matter, around here is steel trunking and pipe for all small power and lx

 

[Paul.M]

Can you elaborate why computers sockets NEED to have a supplementary 4mm Earth. It doesn't say that in BS 7671

It is in there somewhere, I got pulled on it a few years ago by an arse of a local clerk of works. I'll find it and post up tomorrow.

 

[Andy78]

It is in there somewhere, I got pulled on it a few years ago by an arse of a local clerk of works. I'll find it and post up tomorrow.

543.7.1.103 in the BGB.

 

[tazz]

Are you sure about that? All new build school work, and bigger commercial for that matter, around here is steel trunking and pipe for all small power and lx

Agree and have never seen any different, all cable schedules set for schools/commercial have requested steel trunking for low power & lighting, tray for swa, basket for data/security/fire. Then all drops galv tube.

 

[shanky887614]

Are you sure about that? All new build school work, and bigger commercial for that matter, around here is steel trunking and pipe for all small power and lx

it depends on the architect/ clients requests as well.

have done 3 floor hospital building and ward refurbs as well as schools all using basket and fp etc.

when ceilings go back up its easier on basket to make changes

 

[Paul.M]

543.7.1.103 in the BGB.

Thank you Andy, great reg.

In the BYB it is now 543.7.1.203 (ii). There will be at least two or three more Regs about it but that will do for a Saturday night lol.