Upstairs light on downstairs circuit

[ade11]

I live in a council house which has had a lighting rewire by incompetent electricians ( they could not manage a two way circuit amongst many other things). I have found that when I turn off the upstairs lighting circuit the landing light is still working (I had to replace the bulb holder but tested before proceeding). I reported this and an electrician came round and told me this was normal. I pointed out that Joe B&Q replacing the light fitting without testing first could get electrocuted or shocked and thrown down the stairs. His reply was that they should not be working on it if not qualified,not really a valid excuse for exposing someone to danger of death. I think what he told me is BS and the previous cable monkeys tapped a feed from the downstairs circuit rather than do a proper job. Am I right ?

 

[chivers67]

It's quite common to have a Two way circuit feeding two light switches on the Ground floor / Downstairs lighting. It's got to be on one or the other after all what would you suggest?

 

[EFLImpudence]

It is perfectly normal.

 

[sparkwright]

There's nothing wrong with that.

It's allowed.

One good reason may be to eliminate having two circuits within a 2 or 3 gang switch in the hall way. Joe B&Q would have to ensure both circuits are isolated at the mains before replacing a switch.

Also, being a council house, it may originally have been wired in conduit - in which case new single wires would often be pulled in the same way as the old single wires.

(Singles wires in conduit might explain the confusion they had in wiring the 2 way switching - it can get complicated if all the wires are the same colour.)

And I'm afraid he is quite right about Joe B&Q - he should test everything to see if it's live or not vefore starting electrical work - never assume.

 

[oldbutnotdead]

As above, its got to be on one circuit or the other, always test and confirm dead before working on any electrical kit.

 

[Astra99]

I wonder if this landing light is using a borrowed neutral too?

 

[Keithmac]

Our landing is the same, uses downstairs circuit.

You have to verify dead before working on any circuit or fitting regardless of what breakers you've shut off.

 

[Harry Bloomfield]

It is perfectly fine, so long as the neutral is from the same circuit. A neutral used instead from a different circuit would be what is called 'a borrowed neutral' which is very wrong, but sometimes happens. In your case, the landing light is fed from the downstairs circuit, so the neutral should also originate from the downstairs lighting circuit. An easy check (though not absolute proof on its own) would be to look in the ceiling rose of the landing light. There should be only one blue wire in the neutral terminal.

 

[ericmark]

Again no problem, except with duel pole RCBO's the only way to isolate is to turn off the main isolator, MCB's in general do not switch neutrals so if isolated 99 times of of 100 there could be no error.

 

[conny]

One of the main reasons, besides those above, for having an upstairs light on the downstairs circuit and often a down on the up is in case of a failure on one circuit you will still have at least one light working on that floor.
We were taught at college to do this but it was also suggested that this information be placed inside the fuse box, (CU these days), so people would know.

 

[oldbutnotdead]

The above was also a good reason (if fitting one big rcd) to keep lighting off the rcd (for years my house had a 6 way Wylex via RCD for all power & a 4 way for lights. So when the cooker started playing up i could at least see what i was doing

 

[EFLImpudence]

It's quite common to have a Two way circuit feeding two light switches on the Ground floor / Downstairs lighting. It's got to be on one or the other after all what would you suggest?

 

[ade11]

Thanks for the comprehensive replies, I appreciate that one should always test before touching,just had no faith in these guys after having lights flashing on when switched off,shocks off switches,a cable crushed between floorboard and joist and labelling downstairs sockets as up and vice versa on the CP. The two way was in the living room,they took the cable(s) up the wall at one end,under the bedroom floor (where I found the crushed cable) and down the other end wall,so it was their own cabling they could not work out. There is conduit,house was built 100 years ago,so probably had lead originally. They also made an incredible mess,punching holes in the ceilings next to the existing fittings, running cable and then swapping over. Took them about three weeks too,they were part of a scheme to improve a lot of the housing run by a large contractor,their name had something to do with castles....

 

[securespark]

Some sparks are simply incapable of doing sympathetic rewires....

 

[Harry Bloomfield]

There is conduit,house was built 100 years ago,so probably had lead originally.

No, they never used lead inside conduit. Conduit would suggest VIR - rubber insulation, with a waxed cotton over the top.