17th edition quickie

[stedon1]

Have just finshed my second class on my 17th edition course. The tutor has told us that if the cable is buried less than 50mm from the surface or is not protected by steel pipe it must be on an rcd. Fine. If the circuit is wired surface it does not need an rcd. Also fine. Does the surface wiring have to be protected by steel pipe or can it be pvc pipe or mini trunking?

 

[Spark123]

If it is on the surface then it isn't concealed hence does not require RCD protection (unless for some other reason). It can be in whatever you like as long as it affords adequate mechanical protection.

 

[stedon1]

Thats what I thought spark. The tutor said it had to be steel pipe. I was going to tell him he was wrong but decided against it.

 

[Spark123]

On the surface of the wall it can be placcy depending on conditions - if you were installing it where it could take some abuse they it would be better in metal.
If you were installing a twin and earth cable concealed in a wall less than 50mm it doesn't require RCD protection if it is in an earthed metal conduit, unless it requires RCD for another reason.

 

[ban-all-sheds]

It can be in whatever you like as long as it affords adequate mechanical protection.

And if it's a sheathed cable, e.g. twin & earth, it can be in nothing at all, as long as conditions allow.

 

[pdcelec]

Have just finshed my second class on my 17th edition course. The tutor has told us that if the cable is buried less than 50mm from the surface or is not protected by steel pipe it must be on an rcd. Fine. If the circuit is wired surface it does not need an rcd. Also fine. Does the surface wiring have to be protected by steel pipe or can it be pvc pipe or mini trunking?

sure this is an electrical course and not a plumbing one?

 

[hairyben]

You can also bury SWA or *flexishield without RCD protection

*Although, NICEIC tech advice response is "we havn't tested it, so cannot comment, if you're satisfied it meets the requirements you may use it"

 

[stedon1]

Thanks hairyben. Pdcelec if you've nothing constructive to say then dont say anything.

 

[pdcelec]

Thanks hairyben. Pdcelec if you've nothing constructive to say then dont say anything.

It was constructive. Electricians use conduit, plumbers use pipe!

 

[dingbat]

The answer can always be found by carefully reading the appropriate regulations.

In this case: 522.6.6, 522.6.7 and 522.6.8 (including the note underneath).

It is not uncommon, in my experience, for college tutors to have an incomplete understanding of the regulations they teach and to bluster their way out of awkward questions. So, you should always read the regulations themselves, rather than rely entirely on a third party's opinion.

 

[stedon1]

[/quote]It was constructive. Electricians use conduit, plumbers use pipe![/quote] Theres always one!