2 lights in same junction box

[leezer3]

Very quick one really-
I'm currently boarding the loft and sorting things out up there
I've got a junction box on the current lighting circuit which needs replacing. Can anyone see anything wrong with using a junction box with a larger number of connectors, and simply wiring the new light into the same box, rather than adding a second dedicated box?


Cheers

 

[wingcoax]

As long as the jb is accessible there should be no problem.

 

[leezer3]

Time for a little swearing methinks
Actually pulled the current box to bits now (I really don't know what sort of fool wires the box shut because he's lost the screw), and I've got no earthing up here whatsoever, and none in the switches either.
Thinking about it, when I bought the house 5 years ago, most of the light switches were changed from metal to plastic for this reason.

I've got an earth I can easily use for the new lights (New cable goes straight past the socket spur), and while obviously not ideal, I can't see any major reasons why not?

 

[electronicsuk]

I've got an earth I can easily use for the new lights (New cable goes straight past the socket spur), and while obviously not ideal, I can't see any major reasons why not?

If I read correctly, you're suggesting borrowing the earth from another circuit. I'm afraid this is a no-no, as some unsuspecting person could disconnect that circuit in the future, inadvertently removing the earth to your lighting circuit in the future. I'm afraid the only sensible course of action is to rewire the whole circuit with new cable containing a CPC.

 

[leezer3]

I've got an earth I can easily use for the new lights (New cable goes straight past the socket spur), and while obviously not ideal, I can't see any major reasons why not?

If I read correctly, you're suggesting borrowing the earth from another circuit. I'm afraid this is a no-no, as some unsuspecting person could disconnect that circuit in the future, inadvertently removing the earth to your lighting circuit in the future. I'm afraid the only sensible course of action is to rewire the whole circuit with new cable containing a CPC.

It's an earthed metal conduit, so earthing onto that, but basically yes.
Like I said, nowhere near ideal, and doesn't really comply with the regulations, but IMHO safe. I don't buy the unspecting person crap either, there's a difference between something thats very slightly & technically unsafe and something that's going to blow you up!

From having dug out the PIR, it appears to be that the two lights actually connected to this junction box aren't earthed, while everything else is.
Was put down as a Code 4 at the time, as all fittings are plastic.

I'd also note that all the fittings I'm planning on putting in are plastic (including the surface mount backbox), so I'm unsure if this even requires earthing in the first place.

 

[londonboy]

I've got an earth I can easily use for the new lights (New cable goes straight past the socket spur), and while obviously not ideal, I can't see any major reasons why not?

If I read correctly, you're suggesting borrowing the earth from another circuit. I'm afraid this is a no-no, as some unsuspecting person could disconnect that circuit in the future, inadvertently removing the earth to your lighting circuit in the future. I'm afraid the only sensible course of action is to rewire the whole circuit with new cable containing a CPC.

It's an earthed metal conduit, so earthing onto that, but basically yes.
Like I said, nowhere near ideal, and doesn't really comply with the regulations, but IMHO safe. I don't buy the unspecting person crap either, there's a difference between something thats very slightly & technically unsafe and something that's going to blow you up!

From having dug out the PIR, it appears to be that the two lights actually connected to this junction box aren't earthed, while everything else is.
Was put down as a Code 4 at the time, as all fittings are plastic.

I'd also note that all the fittings I'm planning on putting in are plastic (including the surface mount backbox), so I'm unsure if this even requires earthing in the first place.

Yet another one that asks for advice and ignores it.

 

[leezer3]

Not ignoring it at all, I'm questioning the reasoning behind it, and providing a little more specific info as to exactly the situation
There are ideal solutions, and there are ones which are perfectly safe, but technically in an absolute minority of situations may become unsafe.

Even the NIEC seem to suggest that adding a warning label to the CU (Present) and using plastic fittings is acceptable ( http://www.esc.org.uk/pdfs/business-and-community/electrical-industry/BPG1_08.pdf )

 

[ban-all-sheds]

It's an earthed metal conduit, so earthing onto that, but basically yes.

Is it earthed?

How do you know?

Is it continuous?

Have you measured it's impedance?

Where does it run?

Is it obviously the cpc of another circuit?

What's to stop someone removing it or cutting it in the future?

Like I said, nowhere near ideal, and doesn't really comply with the regulations, but IMHO safe.

Your humble opinion is deeply flawed.

I don't buy the unspecting person crap either,

Then you must be hard of thinking.

there's a difference between something thats very slightly & technically unsafe and something that's going to blow you up!

What you propose to do is more than just very slightly & technically unsafe.

 

[leezer3]

The conduit in question is earthed and the impedance readings are on the PIR I've got. Runs down the wall surface of the loft cupboard and into the floor. Earthed to a water pipe I think, would need to check precisely what though.

If you'd care to tell me why it's actually immediately unsafe, I'm listening.
As far as I can see (layman obviously) from the NIEC guidance linked above, it would actually be acceptable, if not recommended with no earth at all.
To my mind therefore, connecting to something already earthed provides the missing earth, and while not being ideal actually makes things safer?

I've got no problems with something being actually unsafe, I'm rather trying to understand
All anyone seems to parrot is that *someone* in the future might decide to remove or break the conduit. I don't deny that's a possibility, but I'm not moving any time soon.

 

[ban-all-sheds]

Earthed to a water pipe I think,

Not allowed.

 

[electronicsuk]

If you'd care to tell me why it's actually immediately unsafe, I'm listening.
As far as I can see (layman obviously) from the NIEC guidance linked above, it would actually be acceptable, if not recommended with no earth at all.
To my mind therefore, connecting to something already earthed provides the missing earth, and while not being ideal actually makes things safer?

While I don't dispute that in a hypothetical situation where there are only two options, class I fittings with no means of earthing at all and class I fittings with earth borrowed from another circuit, to earth would be safer than not doing so. However, there are many other paths available to you to make this circuit safe, but you seem to be immediately discounting them as they will be too much effort, too costly, or in your expert opinion, unnecessary. The reality is that you will never be presented with my 'hypothetical' situation, and even if you were, the best option would be to disconnect the circuit until made safe.

If you go ahead with what you are proposing, what exactly will be the point of the whole exercise? You say that you have plastic faceplates and class II fittings only, so while the earth would be beneficial for future upgrades to lamps and switches, the circuit is not unsafe in its current state if left alone. All you'll do is provide an inadequate means of earthing, which someone, somewhere down the line will assume to be a good earth and, without testing, go and install a load of class I fittings and metal switchplates.

If, as you say, it is only a small portion of the circuit that current doesn't have a CPC, why is it such a large problem to replace the affected wiring?

 

[leezer3]

If, as you say, it is only a small portion of the circuit that current doesn't have a CPC, why is it such a large problem to replace the affected wiring?

It's the lights on the stairs/ front bedroom unfortunately, so basically need to go all the way back to the CU. The stairs have switches at top and bottom, plus a couple of lights, and I'd need to redo pretty large amounts of plaster. Not touching the other lighting circuit, as this has a bathroom on it. Quite whether this'd trigger Part P or not I'm uncertain, but the distance is also much too far for me to want to do this.

I've got no issue with wiring this without an earth & using plastic fittings, but I'm also being told I absolutely *must* have an earth connector
What I'm trying to do is to apply a modicum of common sense to provide the safest possible installation given the constraints.

 

[electronicsuk]

I've got no issue with wiring this without an earth & using plastic fittings, but I'm also being told I absolutely *must* have an earth connector

Told by who

 

[leezer3]

I've got no issue with wiring this without an earth & using plastic fittings, but I'm also being told I absolutely *must* have an earth connector

Told by who

Sorry, have I misinterpreted your initial post?

The way I read that one was that you agreed that an earth was required in case of future changes, as opposed to working around that by wiring with all-plastic, but that you were disagreeing with borrowing an earth from elsewhere?

Like I said before, I'm trying to make anything I do as safe as possible within the constraints of the current install.

 

[electronicsuk]

I've got no issue with wiring this without an earth & using plastic fittings, but I'm also being told I absolutely *must* have an earth connector

Told by who

Sorry, have I misinterpreted your initial post?

To be fair, I didn't help by posing hypothetical situations. The circuit is safe without a CPC as long as all light fittings are class II, and the switch plates are made of plastic. Ideally they should also be attached to the backbox with insulating nylon screws.

The way I read that one was that you agreed that an earth was required in case of future changes, as opposed to working around that by wiring with all-plastic, but that you were disagreeing with borrowing an earth from elsewhere?

You're under no impetus to upgrade the installation to current standards, and as long as you don't install any fittings or switches requiring an earth, the lack of an earth on the lighting circuit does not constitute an unsafe installation.

I definitely disagree with borrowing an earth from elsewhere. Either rewire the whole circuit, or leave it well alone. The latter option seems a little misguided, as I expect you may well regret the lack of a CPC when Mrs. Leezer wants some fancy lights and switches installing! The same could be said should the circuit need extending for any reason in the future.