Lighting Circuit Nuetrals in Domestic Light Switches

[Midwest]

BS 7671, 526.3. Makes a start.

 

[hightower]

Must have been here in my 2365 textbook.

 

[Andy78]

On the subject of accessibility I'm sure I've seen somewhere that a hatch in the floorboards is acceptable for screw type junction boxes. Will try and remember where I saw that. ...

It's debatable really whether or not a hatch is considered accessible or not. I personally only fit MF connections under floors. I may make an exception for a marked board in a central heating cupboard or understairs cupboard that has exposed boards as it is easily spotted and accessed.
A hatch under a floor is only accessible after all the furniture has been moved and the carpet taken up. Not my idea of accessible. And it's only accessible in that manner as long as no laminate/tiles/lino is put down over it.

 

[richy3333]

Hi Again Midwest,

I have installed some down lighting fited with cold running LED's in my kitchen and utility room and downstairs toilet using the existing 3 plate lighting system, I just used a junction box to create the lighting point in each room then looped the switched live and perminant neutral and earth (cpc) from light to light, it all went in very nicely.............. Please dont tell me there is now a Reg that says I should have switched the neutral LOL

Barrie

hope that JB was a MF one

 

[Jay Sparks]

If the OP has used pork pie JB's to connect each down light, then there's no access problem because if they went into the hole for the down light, then they can be easily accessed by the same hole?? I have done this on many occasions. I would never put them under floor boards though. And Wago's are a good idea but they have only been out for 5 maybe 10 years!! How can any one guarantee they are MF??? They haven't been tested long enough.

Jay

 

[DPG]

If the OP has used pork pie JB's to connect each down light, then there's no access problem because if they went into the hole for the down light, then they can be easily accessed by the same hole?? I have done this on many occasions. I would never put them under floor boards though. And Wago's are a good idea but they have only been out for 5 maybe 10 years!! How can any one guarantee they are MF??? They haven't been tested long enough.

Jay

If they have no strain relief for the cables then they need to be fixed though. Daz

 

[Jay Sparks]

If they have no strain relief for the cables then they need to be fixed though. Daz

If the JB is resting on the under side of the ceiling, about 6 inch away from the down light, wheres the strain?? So you pull your down light down and the JB is there. Easy access, no strain??!!

 

[DPG]

If the JB is resting on the under side of the ceiling, about 6 inch away from the down light, wheres the strain?? So you pull your down light down and the JB is there. Easy access, no strain??!!

The strain relief in junction boxes is there so that when the junction box and cables are moved around, the terminations are not put under stress, especially where the relatively non-flexible t&e is used. Daz

 

[Jay Sparks]

The strain relief in junction boxes is there so that when the junction box and cables are moved around, the terminations are not put under stress, especially where the relatively non-flexible t&e is used. Daz

I know what you are trying to say but i just cant see how a downlight is gonna move around when its in a ceiling. Jay

 

[DPG]

I know what you are trying to say but i just cant see how a downlight is gonna move around when its in a ceiling. Jay

It's more the juggling around and moving things around when the boxes are pushed up into the ceiling though. Daz

 

[Simonslimline]

Down-lights have been installed without using strain relief or MF JB's for years without problems surely.

 

[DPG]

Down-lights have been installed without using strain relief or MF JB's for years without problems surely.

So have lots of things, doesn't make it right though. And don't have to be MF when accessible, but still should have strain relief.

The IEE Wiring Regulations state that terminals shall not be subject to undue stress,
i.e. taking weight of cables or fittings.
Currently a high proportion of Junction Boxes are installed behind Downlighters or
decorative light fittings, where moving the Junction Box in to position after wiring
could cause stress on the terminations.

 

[IzzyS]

It's more the juggling around and moving things around when the boxes are pushed up into the ceiling though. Daz

Is that why sockets, switches and cooker control units all have built-in cable restraints? Lots of juggling around especially with 6 & 10 mm cables, and quite likely that a "Part P" decorator will pull them free to tuck the wallpaper into the box or paint round them.

Maybe if the JB is in an accessible place where someone may trip over it, such as a loft then I agree the terminations could conceivably end up under some undue strain. I feel this is another of those regs designed to sell more expensive new products.

Having said all that, I usually use wago boxes or hager MF JBs as they're quicker to wire.

 

[Jay Sparks]

It's more the juggling around and moving things around when the boxes are pushed up into the ceiling though. Daz

ok, so what about the terminal block on top of the down light. Is that classed as inaccessible.
or If they have a transformer. Both of these would have the same problem as you described with the jb.
Jay

 

[DPG]

ok, so what about the terminal block on top of the down light. Is that classed as inaccessible.
or If they have a transformer. Both of these would have the same problem as you described with the jb.
Jay

Possibly so, but the regs state strain relief on JBs that are not fixed, as above. Daz

 

[Simonslimline]

So have lots of things, doesn't make it right though. And don't have to be MF when accessible, but still should have strain relief.

The IEE Wiring Regulations state that terminals shall not be subject to undue stress,
i.e. taking weight of cables or fittings.
Currently a high proportion of Junction Boxes are installed behind Downlighters or
decorative light fittings, where moving the Junction Box in to position after wiring
could cause stress on the terminations.

Personally i have always used Hager J501 junction boxes for down-lights.

Did any of the older style Jb's have strain relief? All the ones i have seen on the job generally don't have it.

 

[DPG]

Quite often, people just used to use the 'normal' brown jbs and leave them dangling under floorboard and god-knows where

 

[7029 dave]

Quite often, people just used to use the 'normal' brown jbs and leave them dangling under floorboard and god-knows where

Always screwed mine down to the joist, Dave tight as good as any MF jb.

 

[DPG]

Always screwed mine down to the joist, Dave tight as good as any MF jb.

Agree. Done up nice and tight and the jb screwed to the joist is good for years. Daz

 

[Jay Sparks]

Ok, so you fix the jb to the joist. The cable that comes from it to the down light will still move around when, as you say, you are messing with the light. Not having it fixed would actually be better for the terminations.
bnin