twin and earth cabling size for commercial buildings

[Risteard]

I wonder why you would be using T&E in a commercial installation. Usually I would be thinking singles in conduit surface mounted all the way through. Alternatively, dado trunking. Personally I hate T&E in commercial, very untidy and inelegant. With singles and conduit/dado trunking you can chop and change to re-fit sockets and lighting at will without going into the fabric of the building. Any fault finding is inestimably easier as is repair and additions. And then of course with T&E you get those situations of spaghetti in the ceilings flopped all over the place and additions add to that over the years. Not a very well designed method imho.

Very well said. T&E is a domestic cable and really isn't generally the right choice in a non-domestic setting.

 

[davesparks]

Thanks for sharing your thoughts. For lower cost which includes getting away with not using trunking for singles, i think these days a few of us are going over to T&E from time to time.

Is that the best approach to design? 'lower costs' and 'getting away with it'?

 

[davesparks]

Very well said. T&E is a domestic cable and really isn't generally the right choice in a non-domestic setting.

T&E is a general purpose cable, there is no rule or regulation limiting its use to domestic installations.

 

[davesparks]

I wonder why you would be using T&E in a commercial installation.

Why not? If T&E is suitable for the job why not use it?

Personally I hate T&E in commercial, very untidy and inelegant.

Surely that is a result of bad workmanship, not a problem caused by the cable itself?

I'm pretty sure a lot of us can produce a much neater and more elegant installation with T&E than some people manage to achieve with other wiring systems.

 

[Risteard]

T&E is a general purpose cable, there is no rule or regulation limiting its use to domestic installations.

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper containment systems etc.

 

[marxman99]

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper containment systems etc.

Hi, from Amtech cable calculations, the cpc is usually less than that you would usually use in an installation. For example, if you use singles then you would use the same size cpc as the live and neutrals, but on calculations it usually can be less. Not every case but usually

 

[default]

I imagine they'll run in the cavity and not in trunking or conduit or tray, probably clipped when i think about it. Can't quite remember how i've seen this done on site. Back in the day it was conduit in the walls probably to costly for that these days. They are circuits for wall sockets. I'm actually a electrical design consultant.

Clipped in a cavity, doesn't sound right. Think the installation method needs looking at a bit more closely.

 

[default]

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper containment systems etc.

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper containment systems etc.

You'd be surprised at the amount of commercial buildings that are wired in T&E, even when they're using trunking.

 

[default]

I was careful not to state that it was generally prohibited, but the generally much higher fault currents on a reduced csa cpc and issues of adequate mechanical protection need to be considered. Really it is intended for domestic type installations and much superior choices exist for non-domestic installations. Let's be honest and agree that generally T&E is simply selected for low cost (comparatively) to proper containment systems etc.

Surely the cable, containment and installation method you choose is dependent on the job your doing no matter if its domestic, commercial or industrial. Otherwise you just over or under engineering the job

 

[Electro-tech]

Probably Building Regs may apply if the cable is run in the cavity. Then get some polystyrene pumped in to help migration.