Why don't lights come with junction boxes built in?

[Stevos]

Hi,

I've recently replaced an ancient crumbling ceiling rose in a toilet with one of these http://www.diy.com/nav/decor/lighting/outdoor-lighting/Vema-Frosted-Shade-Bulk-Head-10307588

I've got it all wired up and working, but as a novice, I'm a bit baffled as to why modern light fittings don't seem to include any kind of junction box for connecting between the switch cable and the lighting circuit. They just seem to have live neutral and earth connections.

As the light is on the end of the circuit, fortunately I only had two sheathed cables in the ceiling at that point - the main lighting cable, and the switch cable - with no additional cable for lights further along the circuit.

In the end I just took both sheathed cables into the light housing, used a 15A choc block to join up the circuit live and the switch cable (then connected the switched live and the neutral across the lamp, and both earths to the housing earth point). The choc block is inside the enclosure with the bulb - visible when you unscrew the shade for bulb replacement - the case / shade unscrews with hand turning wing nuts and doesn't require a tool to open.

So this all works, and in this case doesn't seem to be electrically different to if the light had its own terminals for this, but would be awkward to hook up or swap out a ceiling rose for a light fitting that isn't at the end of the circuit using this method (or to extend the circuit from there) - at which point I'd presumably have to have a junction box.

The cost of adding junction box points into lights would surely have to be minimal (pennies), so I don't get why they don't come with appropriate connection points to avoid hassle and external wiring with more connection points to potentially fail.

I'm pretty sure I haven't made things less safe than they were, as the old fitting was apparently made of something with the texture of cadbury flake, had loose connections, the switch cable wasn't marked, and the (metal) switch plate wasn't properly earthed before I swapped it.

Is the choc block approach an okay thing to do, or would it cause condemnation by the pros? There are no exposed wires and I guess the shroud on the choc block screws should prevent any unwanted contact. Maybe I can just wrap a bit of insulating tape around the block and call it a day? I've read around about it, but wasn't sure if choc blocks in this situation are ok (inside the housing, but in a user servicable area where the bulb is changed.)

 

[Aragorn84]

choc block is fine, why put it next to the lamp and not just beside the other electrical terminations though?

Some light fittings do come with an additional connection for the loop live, it likely is simply penny pinching.

 

[Stevos]

The choc block isn't physically attached to anything (other than the wires), it's just a single connection block inline with the wiring, free floating .

As the wiring is stiff and lengths are restricted, it's not easy to reposition. It's basically to the side and slightly behind the lamp - the other terminals are in a bracket holding the screw mount for the bulb (so behind it). It should be well out of the way for any heat issues (also currently using 11W CFL)

Maybe I should try harder to position it against the housing and glue it in place or something. I wasn't sure if fixing it there might make it less safe (glue melting etc)

Shrug.

 

[ericmark]

Where a light is made for a special purpose it will have the extra connections required my emergency bulk head light for example and some British made lamps do have the extra connection but with a bulk head lamp one would normally want to feed with a single round cable so the stuffing gland will seal from water ingress so in the main the extra connection is not required.

In some countries they use the switch as a junction box rather than the ceiling rose this means longer cables with as a result higher earth loop impedance plus no non switched power to lights to work either emergency lighting, fans or other items so in the main our system works out better but where lamps are made for many countries one can understand why the terminal is not included.

 

[OwainDIYer]

Personally where I am fitting new lights I now run 3+e between the switch and the light, so I have live, switched and neutral at both locations in case I want to add extra lights later.

 

[sparkwright]

The light you have chosen is a difficult one if you have more than one cable. As you have found out, there's not a lot of space.

You should use heatproof sleeving over the entire length of each wire.

Personally, I never run a permanent live and a loop connector block to an outside light. It's best to do the joint at the switch, or failing that a junction box hidden away somewhere. I try to get just one cable at the light position, or two if there's a series of outside lights.

You have to be careful running too many cables into an outside light if it's going to compromise it being watertight. Avoid making your own cable entries, but remember waterproof compound can assist any holes you think may allow water in.

If appearance is not important, perhaps you could have fitted a weatherproof junction box close to the outside light. Always avoid top cable entries, the water always seems to find a way in eventually.

 

[PrenticeBoyofDerry]

I'm a bit baffled as to why modern light fittings don't seem to include any kind of junction box for connecting between the switch cable and the lighting circuit. They just seem to have live neutral and earth connections.

Some do offer the loop-in connector, unfortunately not all, and as an installer sometimes with the restriction of space, it would be an advantage if they did.

In the end I just took both sheathed cables into the light housing, used a 15A choc block to join up the circuit live and the switch cable (then connected the switched live and the neutral across the lamp, and both earths to the housing earth point). The choc block is inside the enclosure with the bulb - visible when you unscrew the shade for bulb replacement - the case / shade unscrews with hand turning wing nuts and doesn't require a tool to open.

It is a standard procedure to use an additional connector to loop the live in to the switch and loop live to live when required. A tool is not required to open an enclosure, but the enclosure must have provisions in place to protect against accidental contact with live parts.

So this all works, and in this case doesn't seem to be electrically different to if the light had its own terminals for this, but would be awkward to hook up or swap out a ceiling rose for a light fitting that isn't at the end of the circuit using this method (or to extend the circuit from there) - at which point I'd presumably have to have a junction box.

Providing space allows within the enclosure, using a connector for the live loop would offer everything you required, no need for bulky junctions.

The cost of adding junction box points into lights would surely have to be minimal (pennies), so I don't get why they don't come with appropriate connection points to avoid hassle and external wiring with more connection points to potentially fail.

As stated previously some do and simply by adding a spare connector would do the trick anyway, if you really wanted where a three point choc block connector was to be found within the enclosure, you could simply replace this with a block of four.

I'm pretty sure I haven't made things less safe than they were

You sound quite contentious and I am sure you haven't, but when items that require earth or continuity of earth, I would test that that protection exists!

Is the choc block approach an okay thing to do

Yes

or would it cause condemnation by the pros?

Not me it wouldn't

There are no exposed wires and I guess the shroud on the choc block screws should prevent any unwanted contact. Maybe I can just wrap a bit of insulating tape around the block and call it a day? I've read around about it, but wasn't sure if choc blocks in this situation are ok (inside the housing, but in a user servicable area where the bulb is changed.)

It is acceptable to do it as you have, "electrical tape" is not an insulator and is not required.