Regulations
- Thread starter mcbonez
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Either. If you are using wiring with loop-in at the lamp, it is easier to power from the upstairs lighting circuit.
There is no "regulation". But you must not borrow a neutral, or a live, from another lighting circuit.
There is no "regulation". But you must not borrow a neutral, or a live, from another lighting circuit.
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Either there is nothing to say which. However where there are two lighting circuits it should not use both. Years ago there was a method used which borrowed a line from an adjacent switch although this could cause mains hum so not recommended it is still not strictly against the regulations. However if you split the lighting supply then this method can result in what is called a borrowed neutral (even though really borrowing the line) which is dangerous for any one working on the system so is against the regulations.
Before RCD protection for lights it was common where lighting demand had increased to split the lighting circuits often people split the circuit without testing to see if the line was shared and this is where the regulation was broken. With RCD protection these faults became evident with the RCD tripping so either the wires between the two switches needed renewing for triple and earth instead of twin and earth or the two lighting circuits needed combining or a RF link is used between the two switches.
I have seem where people have put both lighting circuits on the same RCD but still use different MCB's that breaks the regulations as we still have a borrowed neutral.
As the ceiling rose is also a junction box and is rated 5A one should not really use a 10A MCB also lighting MCB should be B type even if blowing a bulb causes it to trip as this stops the contacts of a bulb blowing welding onto the bulb holder but the regulations allow up to a 16A MCB for lights where of course the junction boxes (ceiling roses) are suitable rated of course.
Before RCD protection for lights it was common where lighting demand had increased to split the lighting circuits often people split the circuit without testing to see if the line was shared and this is where the regulation was broken. With RCD protection these faults became evident with the RCD tripping so either the wires between the two switches needed renewing for triple and earth instead of twin and earth or the two lighting circuits needed combining or a RF link is used between the two switches.
I have seem where people have put both lighting circuits on the same RCD but still use different MCB's that breaks the regulations as we still have a borrowed neutral.
As the ceiling rose is also a junction box and is rated 5A one should not really use a 10A MCB also lighting MCB should be B type even if blowing a bulb causes it to trip as this stops the contacts of a bulb blowing welding onto the bulb holder but the regulations allow up to a 16A MCB for lights where of course the junction boxes (ceiling roses) are suitable rated of course.
Was going to take a supply from upstairs down to master downstairs for landing light upstairs so the breaker turns the landing off on the up lights as its upstairs so is that safe taking a supply from upstairs to a switch downstairs ?
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There's no problem in connecting a switch which is physically downstairs to a light (landing) which is supplied by the 'upstairs lighting circuit'. The important thing, as explained by eric, is that both the neutral and live for the landing light must come from the upstairs lighting circuit.
Kind Regards, John
Yep was going to take the live and neutral the light upstairs then take the split live to the switch downstairs to the master just worried that it's against regs as if someone turned the downlights off on breaker board that switch would still be live downstairs ??
That's always going to be a potential hazard if you want 2-way switching od a landing (or hall) light (i.e. a switch both downstairs and upstairs for the light - which is totally 'standard') and have two or more lighting circuits. If you did it the other way around, and supplied L & N for the landing light from the downstairs lighting circuit, then, although the downstairs switch would be 'safe' (totally dead when downstairs lighting circuit was switched off), the upstairs switch would then be live even if the 'upstairs lighting' was switched off. For this reason, one has to be very careful when working on lighting circuits which do, or may, have cross-floor two-way switching. If there is any doubt, the only safe approach is is to turn of all lighting circuits.
Kind Regards, John
Just so I'm clear what you intend to do because the terminology you are using is confusing.
Because it does sound as if you are thinking about using the landing ceiling rose's live and neutral to the landing switch and then linking to the downstairs switch - in other words you are taking the upstairs neutral downstairs.. While you can do this I'm not sure why you are considering doing it.
If you are using the upstairs lighting circuit. I hope you are taking a permanent live from the landing ceiling rose through the landing switch and back to the ceiling rose. You are connecting the landing switch to the downstairs switch by using strappers.
Hang on - haven't already started a thread on this problem - caused by your 'electrician'?
Having just read the thread it is clear that the electrician, if he existed in the first place, wasn't an electrician especially if he spent three days trying to fix it.
Me thinks the electrician is fictional and in reality you are the one who is doing the wiring for this job. If so please tell the truth - then we can gauge the level of your knowledge and give you the proper advice.
Because it does sound as if you are thinking about using the landing ceiling rose's live and neutral to the landing switch and then linking to the downstairs switch - in other words you are taking the upstairs neutral downstairs.. While you can do this I'm not sure why you are considering doing it.
If you are using the upstairs lighting circuit. I hope you are taking a permanent live from the landing ceiling rose through the landing switch and back to the ceiling rose. You are connecting the landing switch to the downstairs switch by using strappers.
Hang on - haven't already started a thread on this problem - caused by your 'electrician'?
Having just read the thread it is clear that the electrician, if he existed in the first place, wasn't an electrician especially if he spent three days trying to fix it.
Me thinks the electrician is fictional and in reality you are the one who is doing the wiring for this job. If so please tell the truth - then we can gauge the level of your knowledge and give you the proper advice.
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I must say that I hadn't considered that possible interpretation of what the OP has said. As you say/imply, there is no need to (and probably not enough cores in the cable to) take a neutral (from upstairs circuit) down to the downstairs switch - just the usual three cores ('strappers') between the two switches. I took the OP's concern to relate to the fact that this would involve a connection to the upstairs circuit L being physically present in the downstairs switch - which, as I've said, is an inevitable consequence of 2-way switching (when there are multiple lighting circuits), and something one needs to be very careful about when working on lighting circuits.
Kind Regards, John
Ah, I'm not as 'investigative as you' - I tend to take each thread in isolation, on it's own apparent merits. However, now that you point out that that other thread is also his, I agree that you could be right.
Kind Regards, John
Taking a live/neutral from the junction box (coming from fuse board) to the lights then taking the split live down to the bottom switch which is a master which has to be as its a 2 way for a single light at bottom then fetching a 3 core back up to the slave which will work the landing 2way and the proper advice would be get an electrician I no this but he don't seem to no how the electronic switching works and the simple fact you can't put a mains live into a slave ! I do appreciate everyone's help but no that some electricians don't like giving advice because it's there livelyhood which is fair enough
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This is getting much more complicated. Although it's discussed in the other thread (which i didn't initially connect with this one), your question which started this thread said nothing about masters and slaves - hence the fairly simplistic answers you got!
If it's any consolation, I'm not an electrician, so I have no axe to grind.
Kind Regards, John
Right I'm trying really hard to understand what you are saying here but I don't know what you are talking about when you say split live- do you mean 'switched live' or permanent live?
Okay I will assume we are talking about master and slave dimmers - yes - operating a single landing light?
Never liked dimmers on the stairs anyway but...
I think you are taking L/N/E (don't forget the earth) from the JB to the landing light ceiling rose - I assume on the upstairs lighting circuit. From the ceiling rose you are running a permanent live (plus earth) directly to the downstairs switch (master) and returning to the light with the switch live using T&E. Then you are linking the downstairs master with the upstairs (landing) slave via three core and earth cable.
This will work but is there a reason I don't know about why you feel the need to have the master in the hallway and not on the landing thus saving running the live/switch live downstairs?
In a similar vein what if you have an upstairs landing & a downstairs hall light. The landing is on the upstairs circuit with a link down to a switch in the hall. The hall light is on a downstairs circuit with a link to a switch in the hall. Can you use a single 2 gang switch so the 2 circuits are in the same switch & back box or would you have to use two single gang switches in separate boxes?
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