up and down lighting used to be seperate,until council came

Hello all ,not being one for all things electrical,i thought i'd seek out the answer here.

This morning we had all of our electrical switches,sockets, ceiling rose's and lamp holders etc etc ,replaced ,with more up to date versions (single sockets changed for doubles)and also had two mains powered smoke alarms installed,all by our local council.

They did a fine job,except for leaving a 3" hole in the passage ceiling,2 of the ceiling roses hanging off and installing an awful fluorescent light in the bathroom ,(shaped like a ufo),a type of light which effects me physically.

But the thing which is most notable,is ,before they changed the DB for a newer one , we used to have our upstairs and downstairs lighting system separate from each other,each with their own rcd/rccb(correct term ?) ,so if upstairs lighting goes off,downstairs remains on.

But since the renewal this morning,this is all now one lighting system,which to me seems like a step backwards,not an improvement at all,is there a reason why this has been done,as i did hear the lads saying they had problems with the switches which turn on and off the landing light,the type that let you turn on or off the landing light from either downstairs or upstairs,they couldn't turn this light on at all,but all the rest were ok.

Hope you can help with this!

fraser

I forgot to mention that the up stairs switch is a single,where as the downstairs switch is a double,to also turn on the passage light above it.

Please remember this is a guess but what I would expect is that originally the lights were on the same fuse but at some time some one has decided to split them into two circuits.

But years ago when we only had one circuit feeding lights it was common to use just a twin and earth cable between the two 2 way switches used at top and bottom of stairs and this switch would be two gang so either the supply for hall or landing could be linked so saving need for a three core cable.

As time went on it was found this could cause interference in some cases so the practice was stopped and for many years three core cable has been used.

However with the old system if the lights are split between up stairs and down stairs it creates what is called a borrowed neutral really they borrowed live but the result is the same and it is dangerous for anyone working on the system and has been outlawed.

However until a RCD protected consumer unit is used this borrowed neutral is hard to detect and in many cases it can be missed on an inspection but with use of the RCD the fault becomes very obvious and of course has to be corrected. Unless the cable between the two light switches is renewed the only option is to return the two light feeds to be fed from a single MCB.

However because in that case you can't feed lights and sockets in same area from different RCD's and also feed two power circuits for different RCD's using a standard twin RCD board normally the lights need to be feed from a RCBO so they will not fail if something faulty is plugged in.

As to discharge lighting (Fluorescent) there are two main types. Those using a ballast and starter which will give a 100Hz flashing light and those with a high frequency control gear which work in giga hertz range. The latter are unlikely to effect those who suffer from epilepsy. However the HF type do sometimes give off an audio scream which young women can sometimes hear and can result in head aches. But if either is a problem I am sure they could find an alternative lamp. Most Councils say there are Positive to disabled etc and can't see them not changing it.

It may be with only one lighting circuit that they will need to fit battery backed lighting I have one at top of my stairs and since battery backed if there was a fire which would likely trip any RCD I can still see to get down the stairs.

Thanks ,but i'm still not sure about the safety aspect ,one light trips it and we are in total black out,oap you see,and i should say,this borrowed neutral,well before we took over this property (nearly 2 years ago now),the council also renewed the heating system and the wiring for the whole house aswell(why they didn't do the sockets and such also ,baffles me),i'd of thought their sparkies might have spotted and corrected this "borrowed neutral" then,since surely the state of play today is breaking at least one iee reg ?

http://www.i-install.co.uk/diy.htm

Now, assume you have this arrangement and you decide to fit a new light fitting in the bedroom and pull the fuse on the upstairs lighting circuit (or switch off the MCB). You carry out a voltage test on the ceiling light that you are about to disconnect and happy that the circuit is dead you continue to disconnect the wires from the ceiling rose. Whilst wiring up your new light somebody in the house comes up the stairs and turns the staircase light on. Bang! Your dead.

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Or has the change over to the "one" lighting circuit in the db removed/made safe the original wiring mistake(which what i understand you have said),but now left, as i see it,another danger, of being in a total bulb blackout ,even with these RCBO's ,which are installed in my db.

Answering my self here like,this blackout does happen,i flipped the circuit breaker switch for the lighting and all the lights went off,not something i'm happy with at all !

And would like to have the council make the lighting electrically correct to what i suppose 99% of the country has theirs?

Reg 314 - 01 - 04 ?

Biscuitbouy,the answer to making it back into the one circuit,has been answered on this forum previously,

Lectrician
To make it obvious it is a single circuit - lowers the chances of someone seeing two lives in an MCB at splitting them.

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My guess is that, as eric says, there is a "borrowed neutral". I also surmise that the council originally put the two original lighting circuits into either separate RCBO's or into MCB's each protected by a different RCD.

This means, with the borrowed neutral scenario, that every time you energise the landing light, thr RCBO's or RCD's will operate. The only way to reinstate the lighting as two separate circuits is to alter the two-way setup to eliminate this shared wiring.

This can usually be achieved by eliminating the live feed to the landing switch on the ground floor and replacing it with a live feed sourced from the first floor circuit.

I could argue that all the lighting was interconnected by the borrowed neutral, so the previous arrangement was one circuit fed by two fuses, but that doesn't really get anyone anywhere.

Seperating the lighting into two circuits will probably involve rewiring parts of one or both lighting circuits, and the attendant damage to decor etc.

A couple of strategically placed table lamps running from power sockets, and / or a battery backed landing light fitting as described by ericmark could provide you with some alternative lighting source.

Simply put, if you are not happy with what has been done, contact your council, get them to send someone out who can either sort your issues out or explain the reasoning behind the changes.
Ask for a different light fitting in the bathroom if this one causes you medical problems.

If you have a complete power failure now it will be not different to a complete power failure before. And one would normally keep a torch or candle somewhere it can be easy found with a complete power failure.

As to any RCD or MCB tripping you would normally use table or standard lighting to cover for this eventuality if the power and lighting for one area is on same MCB then this is of course wrong as to RCD this would depend on likely hood of RCD tripping with 30ma non delayed this would normally be seen as not complying with

314.1 Every installation shall be divided into circuits, as necessary, to:
(iii) take account of danger that may arise from the failure of a single circuit such as a lighting circuit.

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But this is only a problem where lighting and power for same area share the same RCD. Many councils now use RCBO's which would present no problem.

If as you say

biscuitbouy said:

before we took over this property (nearly 2 years ago now),the council also renewed the heating system and the wiring for the whole house as well

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then there should not be a problem with borrowed neutrals.

What is a little odd is the Installation Certificate has to be supplied to person ordering work and should be passed on to owner so a tenant would not necessary see any report. However the completion certificate issued under Part P is supplied to occupant within 30 days. So unless your the owner although you will get a bit of paper to say the work is complete and to standard you will not get details of what was done or why.

With the introduction of energy saving luminaires the power required for lighting is greatly reduced and now the whole house can be supplied by 6A where as before the energy saving drive kitchen lights alone could reach the 6A limit through standard ceiling roses. (Note lights are allowed up to 16A MCB but not if the ceiling rose is rated 6A as most are.)

Although it does on the surface seem a backwards step to combine the lights onto one circuit it is not against any rules. A torch like this removes any danger and at £14.15 are not expensive and I use similar torch until I fitted something similar to this again not expensive at £12.50 and if you are worried about power failure items like those shown work even if all your power fails. I actually used one of these at £39 which allowed me to select a more in keeping lamp and it works both as standard lamp and emergency it is of course HF so no flicker and tubes last longer fitted in 1994 never changed the tubes.

Thanks for the answers,most helpful !

I will get the cfl removed,being in the bathroom ,this is a light which is rarely used to begin with ,so any so called energy saving aspect to be gained would be minimal,taking into account that lighting makes up only a small percentage of people's energy cost anyway ,and considering i didn't and most probably don't know they contain mercury (and have just thrown these things in the dustbin for the local tip ,hardly environmentally friendly having 1000's of these things leaking into the soil),with specific methods advised for clean up and disposal if they break or spill their contents,and with no local services in place for safe disposal.

They don't even have warnings on or inside packages informing people what to do with breakages,certainly these things are not safe when you have small children or pets around,knocking things over!

You don't have these health hazards with a normal bulb.

Fluorescent lights contain mercury vapour, stringent recommendations apply regarding broken lamps relating to room ventilation and disposal of the lamp parts.
Typically, a room should be closed off with ventilation to the outside and vacated for about 15 minutes, and then parts picked up into a plastic bag using rubber gloves, the bag sealed off and sent for recycling, vacuum cleaning up the parts is expressly not advised

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Even with emergency lighting, would anybody here really sign a declaration saying that to the BEST of their knowledge and belief an installation with a single lighting circuit in a 2-storey house complies with BS 7671:2008?

"normal bulb"s are being phased out. the 100 watt bulb has already been withdrawn as far as i know. all tungsten filaments including halogens are being withdrawn.

i kid you not.

And a high frequency CFL or fluorescent lamp will not produce any adverse effects to a human being. The flickering is something like 30KHz - 30,000 times per second. Nobody can detect that.

Different colour tubes are available too - 2700-3500k is warm white, 4000k is white, 4500k is cool white, 6400k is daylight. The colours make all the difference. They are printed on the ends.