17th edition 1st fix.

[iansmith7]

Hi everyone
Im an Industrial electrician qualified to the 16th edition regs and I have done a few rewires over the years but not since the 17th came out. I will be doing the new regs in march through he company I work for. However I need to do a first fix for a kitchen & downstairs ring main next week. It would be helpful to know the answers to the following questions:

1. Socket height minimum 450mm?
2. Cables under plastic capping in a channel in the brick (if less than 50mm deep must be 30mA rcd protected)?
3. Earths from CH rads (are Required?) connected to nearest socket. (2.5 or 6mm?)
4. Socket height above kitchen work top?
5. Appliances under worktops should have spur unit isolation above the worktop? (Wired to a single socket or appliance outlet under the worktop?)
6. Is it Ok to put surface mounted sockets inside base units for appliances?
7. Do cables under suspended floors need to be clipped to the joists?
8. Seperate Ring Main for kitchen is now a requirement of the regs?
9 Gas boiler is in the kitchen does this need an earth bond (size?) direct back to main the main earth ( Gas incomer is not in the kitchen but next to the electric incomer).

A bit of a long list I know but any hints in line with the 17th edition are appreciated.
Cheers
Ian

 

[ricicle]

1. Not in this case
2. Yes, if normal t+e
3. No
4. So as not to strain flexes
5. A good idea if socket becomes hard to get at (better as flex outlet to keep fuses above level
6. Yes, but better to fit on the more substantial sides than flimsy back hardboard.
7.Should be
8.Not a reg. but a good idea
9.No

 

[dingbat]

It would be helpful to know the answers to the following questions:

2. Cables under plastic capping in a channel in the brick (if less than 50mm deep must be 30mA rcd protected)?

A bit of a long list I know but any hints in line with the 17th edition are appreciated.
Cheers
Ian

The only thing on your list that has changed w.r.t 17th Edition is Number 2. And, yes, 30mA RCD required.

(Number 3 worries me though. Why did you ever think that was needed? You might want to consider our two-day earthing & bonding seminar! )

 

[iansmith7]

Hi thanks for your replies,

After I had posted these questions i read a thread about bonding extraneous metal parts that included some of your posts dingbat and I plead guilty to thinking just about any thing made of metal that was part of an electrically powered machine or system had to be bonded to a local earth. I think I formed this opinion due to my lack of understanding (through poor instruction?) and thought it was "safer" to just bond everything. Thanks to you and other members of this forum for putting me right on that score.

ricicle when does that minimum socket height apply? (I will be rewiring the whole house not just the kitchen). If I bring the T&E out of the wall onto the cabinet side it would need to be in plastic trunking?

And finally in this post, lighting ccts must now be rcd protected (seperately from power circuits at ??mA) does this only apply if the cables are less than 50mm deep?

thanks for your help
Ian

 

[dingbat]

After I had posted these questions i read a thread about bonding extraneous metal parts that included some of your posts dingbat and I plead guilty to thinking just about any thing made of metal that was part of an electrically powered machine or system had to be bonded to a local earth. I think I formed this opinion due to my lack of understanding (through poor instruction?) and thought it was "safer" to just bond everything. Thanks to you and other members of this forum for putting me right on that score.

Ian

Happy to help. The comment about poor instruction is pertinent. I meet electricians every day of my working life and I regularly get college lecturers attending courses. I have been quite appalled as to just how poorly understood is the subject of earthing and bonding, regardless of length of time served, variety of experience and level of qualification and/or authority.

 

[dingbat]

And finally in this post, lighting ccts must now be rcd protected (seperately from power circuits at ??mA) does this only apply if the cables are less than 50mm deep?

There is no requirement to RCD-protect any lighting circuit (although there is a 'recommendation' for lighting in telephone kiosks, bus shelters, etc). The requirement you are thinking about is applied to the cables, not to the equipment those cables serve.