which code

[stevep23]

Hi Folks
First a bit about me. I work as a multi skilled technician with a electrical bias for a large company in the north west, with redundancy looming I decided to concentrate on the electrical side of my training back in 2008 and successfully completed 2391, with a view to going it alone. At the last minute I had the rug pulled from under me and couldn’t go with the redundancy payment which would of helped to get things going, it didn’t seem to be a good thing at the time but I realise I probably had a lucky escape seeing how some of you guys have had a tough time in past few years. Hope things pick up soon.
I have carried out a periodic inspection for a friend who is having a really hard time at the moment with serious illness in the family and youngsters to look after. My question is about which code for a DB in his garage with the 6mm T&E supply from the main consumer unit in the house. The cable is in plastic trunking for the first 2 meters up the wall on the outside of the house and from then on clipped direct until it reaches the garage. There is a water point below the garage DB and the supply characteristics for house is TN-C-S. I have read a lot on the site about exporting/ not exporting PME but could do with some help.

 

[telectrix]

how is the 6mm protected at the CU? is it from a MCB or henley blocked?

 

[jaresquire]

Is the water point metallic or non-conducting?

 

[stevep23]

The 6mm is in the trunking before passing through the wall and cavity into the CU and a 32A MCB

 

[stevep23]

The water point is 15mm copper pipe

 

[telectrix]

the cpc in that 6mm T/E is only 2.5mm, not sufficient csa to bond the water pipe in the garage back to the MET. either run a separate 10mm from MET to garage water, or make the garage TT. ( all circuits in the garage would require a 30mA RCD ).

 

[stevep23]

Thanks telectrix I have suggested making garage TT but because of time [FONT=&quot] constaints etc the work could not be carried out so need to enter this on the certificate would you enter this as a code 1?
[/FONT]

 

[telectrix]

code 2 IMO. it's not an immediate danger. i would, however , fix a bond to the water, assuming it's an extraneous conductive part.

 

[stevep23]

Thanks again telectrix water does have bond and cu's main isolation is via 30mA RCD

 

[telectrix]

might only warrant a code 4 then. if it complied with the regs. at the time of installation.

 

[Bul]

Telectrix
Can you explain a bit about "or make the garage TT". It's just that I have never heard of a sub circuit(?) this way. How would this be done in practice?

 

[telectrix]

you disconnect the cpc of the feed cable at the load end, then whack a rod in to earth the garage installation.

 

[opsman]

T&E cable shouldn't be clipped direct outside. It isn't suitable for the solar radiation it will be subjected to and will degrade over time. It should have some form of mechanical protection i.e conduit or trunking. This constitutes a code 2 departure.

 

[Farmelectrics]

how many rods would you put in telectrix would you be ghappy with one

 

[D80]

T&E cable shouldn't be clipped direct outside. It isn't suitable for the solar radiation it will be subjected to and will degrade over time. It should have some form of mechanical protection i.e conduit or trunking. This constitutes a code 2 departure.

It may be just that we don't get a lot of sun in Northern Ireland, but I've seen T&E clipped direct outside showing no signs of problems after almost 30 years...

 

[opsman]

Part P of building regs states:

5.7 Garden Lighting and power
Outdoor lighting and power, and electrical installationsin sheds, garages and greenhouses are within the scope of Part P of thebuilding regulations. Furthermore, outdoor lighting and outdoor power circuitsare not exempt from the minor works relaxation. The addition of a lightingpoint or socket-outlet to an existing outdoor lighting or power circuit isnotifiable work.

5.7.2 Fixed cables

PVC cables must be protected against direct exposure tosunlight. Cables must be permanently fixed in a protected location ormechanically protected or buried.
Cables need to be shielded against prolonged exposure todirect sunlight, particularly grey and white PVC cables. Cables with a black orrubber sheath are recommended if direct exposure cannot be avoided. Ultravioletlight from the sun will degrade pvc and unless shielded will shorten the life.Black pvc and rubber cables have a reasonable life outdoors.

 

[mo the test]

I would recommend code c3. The new condition report makes it easier for the client to know what you as an electrician recommend.

 

[opsman]

Come January I would agree C3. Howver we use Amtech software to produce our certs and they won't be issuing the upgraded software for a few more weeks. So we are still doing periodic inspections rather than EICRs therefore Code 2 (Requires Improvement) applies for now.

 

[HandySparks]

Part P of building regs states:
5.7 Garden Lighting and power...

No it doesn't. You're quoting from the Electrician's Guide to the Building Regulations, which is a different thing entirely.

 

[Engineer54]

Part P of building regs states:

5.7 Garden Lighting and power
Outdoor lighting and power, and electrical installationsin sheds, garages and greenhouses are within the scope of Part P of thebuilding regulations. Furthermore, outdoor lighting and outdoor power circuitsare not exempt from the minor works relaxation. The addition of a lightingpoint or socket-outlet to an existing outdoor lighting or power circuit isnotifiable work.

5.7.2 Fixed cables

PVC cables must be protected against direct exposure tosunlight. Cables must be permanently fixed in a protected location ormechanically protected or buried.
Cables need to be shielded against prolonged exposure todirect sunlight, particularly grey and white PVC cables. Cables with a black orrubber sheath are recommended if direct exposure cannot be avoided. Ultravioletlight from the sun will degrade pvc and unless shielded will shorten the life.Black pvc and rubber cables have a reasonable life outdoors.

What a load of dribble!!

FACT: ...Black cables no mater what their make-up is, absorb heat more readily, whereas White or light coloured cables reflect heat!! PVC cabling suffers far more being exposed to freezing conditions, than from sunlight/ultra violet, not that UK see's much in the way of high ultra violet rays anyway!!

SWA PVC coverings can have a special chemical make-up, that helps immunity to ultra violet rays and other environmental conditions etc. But in countries like the Middle East and Far East roof cables run on tray-work will still require sun shields (not covers) that are raised off the tray by legs to allow air circulation and there-by heat dissipation

As others have said, i've seen what was a white T&E run externally for a good 20 m that was still good 25 or so years later, when it was replaced for a direct buried SWA cable. The colour was now a dirty orangey colour mind, but a bit of jiff and a Scotch pad brought the colour back, and was used again to supply a socket in the garage!!