Electrical Wiring

[orpheus454]

We've got your normal Thai single storey rendered brick house, to which I'm in the process of adding a room upstairs with steel framing.

We're basically up to the internal lining stage, and the electricians have put in the wiring, using the normal 2 or 3 core white PVC covered wiring (eg 2.5/2.5/1.5 3 core for the power points, 2x1.5 for the lighting).

As it's in steel frames, we've put all the wiring in 1/2" PVC conduit, in case of rats, etc, as I thought the incremental cost was worth the extra safety.

Now a friend has come around and says that's not allowed: that any wiring within walls, and especially in conduit, must be single strand wiring (ie instead of a 3 core, 3 single strands) so any heat can dissipate more readily. It's a Thai standards issue, he says, and that if inspected it would not pass.

Is he right?

My question is basically about the Thai building code, but in a general sense surely any wiring to the correct standards is not going to generate much heat. There will be no air conditioning or other high current draw stuff upstairs. The most current draw would conceivably come from using a 1200W belt sander.

Any comments appreciated. Thanks.

[Wee Jimmy]

Never heard of this and my house which was built by a local builder has buried wires through conduit. I didn’t put the wire in the loft through conduit but I wish we had as we were bothered with rats a couple of years ago. I’m going to say your friend is wrong but I’ll keep watching this thread for comments from other members.

Wee Jimmy.

[bankruatsteve]

As there is no Thai "code" that anybody can find - don't worry. Anyway... PVC within conduit is not an issue and certainly fits most other codes. <deleted> is your "friend"?

[Crossy]

Nothing wrong with putting TPE in conduit, it would pass UK IEE Regs 17th Edition, so no issue with Thai regs.

If in conduit it should be de-rated somewhat see here http://www.tlc-direct.co.uk/Figures/Tab4.7.htm but 2.5mm² on a 20A breaker as is normal here will be just fine in most situations.

What would be useful is a copy of the code he's referring to as nobody has yet managed to come up with a set of domestic wiring regulations.

[orpheus454]

Nothing wrong with putting TPE in conduit, it would pass UK IEE Regs 17th Edition, so no issue with Thai regs.

If in conduit it should be de-rated somewhat see here http://www.tlc-direc...ures/Tab4.7.htm but 2.5mm² on a 20A breaker as is normal here will be just fine in most situations.

What would be useful is a copy of the code he's referring to as nobody has yet managed to come up with a set of domestic wiring regulations.

Thanks for all replies.

This bloke generally seems to have a good idea about building stuff, but clearly off the beam somewhat here.

The Whitfield table is interesting, Crossy. Any idea of the reason for the de-rating? Could it be retained heat?

I'll ask him what regulations he's referring to when I see him next (might not be until the weekend, though) and will post response here.

l did a bit of googling myself, and found that there actually are limits to what can be put into various conduit sizes, eg:

http://ths.gardenweb...1003331911.html

Pretty sure I'm nowhere near those limits with me' upstairs room, though...

Thanks again to all.

[orpheus454]

I didn't put the wire in the loft through conduit but I wish we had as we were bothered with rats a couple of years ago.

Yep, I'm guessing that the vast majority of places will have the wires running directly on top of the ceiling battens.

And there'll probably be no problems, but with 1/2" conduit at 10 baht per metre it's pretty cheap peace of mind, eh?

Thanks for getting back.