Domestic premises : loft wiring

[dingodeano]

Any ideas , tips or solutions how to keep cables nice and tidy and out of the way of loft insulation. thx in advance.

 

[RF Lighting]

 

[dingodeano]

Cable tray i like it. What do you do if you need to do a single cable drop away from the edge where your tray is do you do the whole loft?

 

[RF Lighting]

You have little option but to clip it to the edge of the joist, and derate accordingly.

Tray for the whole loft is a bit overkill.

I don't like to see cables clipped to the top of joists as there is too much risk of them being trodden on / having stuff dumped onto them.

 

[firegazer]

You could use lay boards. I used gravel boards in mine.

Used in the same way as the picture but the cables can be clipped onto the board together in groups using an appropriate size of cable clip, e.g three 1.5mm T+E on their ends go nicely into a 4mm clip.

If you have CATV or coax then this can be grouped nicely in to a half round shape and secured with plastic coated steel band. Comes on a reel with holes in it for screws, sorry but I cant remember the name of it.

Looks a pucker job when its all done, but takes a while getting all the cables straight!

 

[dingbat]

YouUsed in the same way as the picture but the cables can be clipped onto the board together in groups using an appropriate size of cable clip, e.g three 1.5mm T+E on their ends go nicely into a 4mm clip!

TUt, tut... Flat twin and earth cable is designed to be clipped flat, not on edge. You are supposed to use the correct-sized clip for the cable.

(For reference, see Regs (16th) 133-01-01 & 522-06-01)

 

[stargazer]

RF Lighting you must be the neatest and most organised electrician in the world
We want to have your babies

 

[firegazer]

So dingbat if you have several cables you clip them all individually do you??

Maybe you could point it out to me?

 

[JohnD]

...We want to have your babies

Has he got any babies to spare? What do you plan to do with them?

 

[dingbat]

So dingbat if you have several cables you clip them all individually do you??

Not necessarily; there are other options. There are spring clips (see Spit Pulsa accessories, for instance) designed to hold several cables and you can always use tray or trunking. But, if you are using purpose-made, twin-and-earth clips the only approved method is to clip the cables individually with the correct-sized clips.

Clipping twin and earth cable on edge has always been a no-no. (So much so, that it has been a standard defect on the 2391 inspection board for many years.)

 

[firegazer]

No mention was made by building control when they inspected my first fix wiring prior to plastering. I really would like to see the actual document that says its a no no. Cos as long as the cables are not damaged I dont see the problem.

 

[dingbat]

No mention was made by building control when they inspected my first fix wiring prior to plastering.

I'm not in the least bit surprised. Some BCOs seem happy to sign off on electrical work after the merest glance... because they are not electricians.

I really would like to see the actual document that says its a no no. Cos as long as the cables are not damaged I dont see the problem.

The problem is that the cable is designed to be clipped flat and clipping on edge can damage the insulation internally with little or no indication to the naked eye. I have encountered cables damaged this way a number of times.

As for a reference, the Wiring Regulations specify that "Good workmanship and proper materials shall be used" (133-01-01) and that "Wiring systems shall be selected and erected so as to minimize mechanical damage..." (522-06-02)

Furthermore, the 17th edition adds (in reg 134.1.1) "Electrical equipment shall be installed in accordance with the instructions provided by the manufacturer of the equipment." (Electrical Equipment being defined as, "Any equipment for such purposes as generation, conversion, transmission, distribution or utilisation of electrical energy, such as machines, transformers, apparatus, measuring instruments, protective devices, wiring systems, accessories, appliances and luminaires." The manufacturers produce a clip specifically designed to clip flat twin and earth cable in a flat manner.

And if you want a 'best-practice' reference you could look up 'Snag 37' in the NICEIC's 'Snags and Solutions' Part 2.
(If you can get a hold of a copy, the Electrical Safety Council's Technical Manual will also steer you straight.)

But, there's no need to be so defensive about it. As evidenced on this very site, many practising electricians are innocently (as opposed to maliciously) ignorant of many of the rules.

 

[ppuch1]

e.g three 1.5mm T+E on their ends go nicely into a 4mm clip.

If cable clips were mean't to be used this way then the manufacturers would make em!

if you clip each cable seperately then you would stagger the clips.

 

[stargazer]

...We want to have your babies

What do you plan to do with them?

I shall raise them into an army of ruthlessly efficient electricians, all working for me, and make loadsamoney.

Give me your babies

 

[Marco1976]

Having paid nearly 4k for a s...e rewire done by a Part P qualified and reccomended spark I must say that I would have personally paid accomodation and food in a nice hotel for the electrician that installs to the above standard. I would not have battered an eye lid if I was to pay 5k for my rewire but this was the standard.

Why can't the industry achieve some sort of consistency across the board in terms of finish and above all safety?