Twin and Earth into flush light fitting

[Ken778]

Hi,

I've got one of these which I'd like to install:
http://www.amazon.co.uk/Micromark-MM18541-Kingston-Luminaire-Chrome/dp/B000EBGKAE

Inside there is a choc-block next to the lamp holder which I would have thought you could just connect the 1.5mm T&E (loops at the switch so only 1 or 2 cables to connect).
Now, looking at another one already installed, whoever did it connected three H05S-U singles to the internal choc-block and then connected these to the T&E with another block left flapping about in the ceiling void.
Wanting to avoid the unenclosed connections, can I just run T&E straight into the light?
Since these lights will only be used with 15-20W CFLs (or 60W incandescent bulbs) , do I really need high-temperature cable/flex?

Thank you!

 

[PrenticeBoyofDerry]

What does the manufacturer recommend?
If you wish to use T&E then I would consider sleeving cables with "Heat Resistant Cable Sleeving"

http://www.tlc-direct.co.uk/Main_Index/Cable_Accessories_Index/Sleeving_1/index.html

 

[Ken778]

I didn't buy it new so no instructions! Also couldn't find any online.

Would you only sleeve the inner cores of the T&E?
Normally I would make sure the outer sheath of the T&E is inside the fitting (or back box or whatever) but in this case should I strip the cable longer and only bring the sleeved cores inside the light?

Thanks for your help!

 

[PrenticeBoyofDerry]

You must always have the grey sheath within the accessory at least 10mm.
I would comply to the 10mm-20mm rule, then sleeve the insulated cores of the T&E and also sleeve the bare CPC/Earth green and yellow PVC prior to protecting from heat.

 

[sparkwright]

What 10-20 mm rule? You don't need as much as 10 mm of sheath entering the accessory. As long as the sheath enters the box, that's fine. Usually a fitting only comes with heat sleeving to fit single cores, so if the minimum amount of sheath enters the fitting, you can sleeve the inner wires then everything should be reasonably protected from heat.

 

[Ken778]

I'll make sure the outer sheath comes into the light fitting and buy some heat sleeving tomorrow.
I also notice that these lights have the cable entry hole right next to the bulb holder!
I've found that I can re position the bulb holder in the lamp to be further away from the cable entry.... The glass cover still fits but I guess the light won't be coming from the middle any more.

Thanks for your help!

 

[sparkwright]

Usually it's a great struggle if more than two twin and earth cables are present in these type of fittings.

If there's more than two cables, and an additional connector block is also required, I tend to fit a junction box in the ceiling void, with just one cable going into the fitting.

Also, if there's some slack on the cables, avoid shortening it. Push it into the void (if there is one) as if the wires do get burnt you will have another chance to re-terminate it.

Bit of a rubbish design those lights in a way.

 

[Chri5]

I'd leave the lamp hold as intended by the maker and wire it up, then test the lamp holder for heat after an hour or three of run time.

If it does get overly hot then maybe a hole saw and suitable gland / or grommet is your friend. Modifying the entry is easier than modifying the holder position and as you pointed out, the light would then not be centred which you will notice every time it's on.

 

[ban-all-sheds]

Use a CFL - no cable melting issues.

 

[bernardgreen]

Use a CFL - no cable melting issues.

Use a good quality CFL

Some cheapo makes get hot and the heat source is concentrated close to the holder. Unlike the filament lamps where the heat source is in the glass and not close to the holder.

 

[PrenticeBoyofDerry]

What 10-20 mm rule? You don't need as much as 10 mm of sheath entering the accessory. As long as the sheath enters the box,

Rule of thumb, I know the regulation only ask for the sheath to enter the accessory. So the general guidance I would give, would be at least 10mm, anything less could lead to errors. Especially considering protection against abrasive action on insulation during fixing.
I thought it was standard procedure to recommend and apply at least 10mm of sheath at entry point.

 

[sparkybird]

What I would do is use a junction box to make the connections and then run a single length of 3 core flex into the light - this will be much easier to deal with. As the light is quite big, you can make a hole in the ceiling behind it so that the junction box will sit in the ceiling and cover said hole with the new light

If you ever need to access the junction box - simply take down the light

Those are pretty cheap fittings and you'll struggle to get more than a single conductor into the terminals I would imagine...

 

[sparkwright]

If you want a really tidy job, and the ceiling is plasterboard, use a circular dry line box. This may make it convenient if you want to change the light fitting for a different type later.

 

[Ken778]

Thanks for the advice!

I had to run T&E into the new light due to the wooden supports in the ceiling making it impossible to make a hole directly under the light so I sleeved the inner cores as suggested.

I decided to sort out the floating choc-block behind the other two lights by adding a chocbox however, when I went to buy one from the local electrician's shop the electrician told me that they are no longer allowed and he doesn't sell/use them!
Apparently, because the choc-block is not fixed inside the box this is now against the regs! Is this now the case? (I have used these in the past and never heard of this.)

He sold me two click connectors:
http://www.tlc-direct.co.uk/Products/TLCT100C.html
which I have wired up and pushed into the ceiling void (and have run heat resistant flex to the light fittings).
However when wiring them I notice that they have no cord grips on the "fixed wiring" side but also no way of securing them in the ceiling. (chocboxes had cord grips!)

Are you allowed to use a junction box with no cord grip when it's used with "fixed wiring"?
I suppose if I had used a circular dry-lining box (which would probably have been better than the click connectors) with some choc-block or wago connectors there would be no cord grip either.

Thanks again!

 

[flameport]

Apparently, because the choc-block is not fixed inside the box this is now against the regs! Is this now the case?

All lies, either the shop person wants to sell you more expensive alternatives, or they have been reading a certain book by Mr Scaddan which claims that the connector 'should always be fixed to a base'.

Are you allowed to use a junction box with no cord grip when it's used with "fixed wiring"?

The answer is - only if the junction box is fixed to a base.

In reality, the issue is whether the cables/wires are properly secured to prevent them being pulled out of the terminals.
A chocbox or similar with cable grip is fine.
A piece of chocblock shoved into the ceiling on its own is not.
A junction box which is screwed to a joist with cables clipped either side is fine.
A junction box hanging from cables is not.