Someone please explain!

[simonatlondon]

Someone please explain the following situation. All thoughts and insults are most welcome.

Problem 1: 2 way switches switching only one 230v downlight. Live and neutral at the jb above in ceiling no problem. Getting 230v. Downlight connected to neutral. Live feed going to switch, I only get 12v. What the f@#k? So light doesn't work. I took temporary t and e from jb to light switch to bypass the switch line, it worked. So it will just need a new switch line.

Problem 2: Light in study worked yesterday. I go there this morning, find fault with 2 way light. I get a call this afternoon "light in study and living room don't work". I go back, take study light fitting down, I find the t and e feeding the light fitting has no neutral but 2 lives instead. Does anyone think the customer is lying to me? I really don't know what to make of it.

This house was an old coach house wired around 15 years ago in my opinion.

Any help would be massively helpful guys. But I have reached the limit today

 

[The Godfather]

Problem 1

Have you checked continuity from the light switch to the live feed at the ceiling point?

Don

 

[SPECIAL LOCATION]

Problem 1Have you checked continuity from the light switch to the live feed at the ceiling point?

Don

Just been pondering this one Don?

think they are both the same problem?

crossed wire at a fitting somewhere...

just doing a quick sketch to upload..

coming soon.....

 

[SPECIAL LOCATION]

Someone please explain the following situation. All thoughts and insults are most welcome.Problem 1: 2 way switches switching only one 230v downlight. Live and neutral at the jb above in ceiling no problem. Getting 230v. Downlight connected to neutral. Live feed going to switch, I only get 12v. What the f@#k? So light doesn't work. I took temporary t and e from jb to light switch to bypass the switch line, it worked. So it will just need a new switch line.

Problem 2: Light in study worked yesterday. I go there this morning, find fault with 2 way light. I get a call this afternoon "light in study and living room don't work". I go back, take study light fitting down, I find the t and e feeding the light fitting has no neutral but 2 lives instead. Does anyone think the customer is lying to me? I really don't know what to make of it.

This house was an old coach house wired around 15 years ago in my opinion.

Any help would be massively helpful guys. But I have reached the limit today

Hello Simonatlondon...

welcome M8!

few point to consider here..

Re P/1

Live feed going to switch, I only get 12v.

If you get your meter and connect the one probe to live..

but leave the other probe open circuit..

your meter will probably show between 9V - 20V..

depending on if the probe is lying on the desk or being held in your hand..

{try is at home & see what you get? }

I think your 12v reading is actually from a live and to an open circuit neutral!

Re P/2

I think a light fitting has been replaced and a wire crossed when reterminatred...

e.g.

Excuse my scrappy drawing but

consider 4 lights in a circuit as shown..

between lights 'B' & 'C'

the neutral supply for lights 'C' (and then onto 'D') is connected to switched live from switch 'B'

{say a black switched live, with no red sleeve/tape.. so mistakenly thought to be neutral?}

If you are reading your voltage across live at switch 'C'

then if no bulb in 'B' there will be no neutral! thus your 12v reading.

and If NO bulb in 'B'.. lights 'C' and 'D' will not work!

If switch 'B' off and have a bulb in B.. lights 'C' and 'D' will work but dim!

If switch 'B' is ON.. then bulb 'B' will come on... but 'C' and 'D' will go off

and you will appear to have two lives at lights 'C' & 'D' and NO neutral!

Oh also no the customer is not lying?

If you followed all that....

can you now explain it to me! :^O:^O:^O:^O

Sorry..

forgot the insults...

KME's a Guinness drinker!!!

was that any good? ]

 

[steptoe]

I really cant understand how the cross wiring is happening,

cos Im thick you see, but I dont understand why its not working, SORRY

 

[ABC Technical]

You most certainly are NOT thick steps, you give some good advice on this here forum you do mate.

 

[simonatlondon]

Hi guys thanks for the responses. T

Thanks Godfather, I didin't measure the resistance of the switch line yet, I will when I get back Wednesday time.

Thanks for the diagram Special Location. Im gonna have to do some bashing to find these jb's.

All im going to say is, what a dump?

 

[SPECIAL LOCATION]

Hi guys thanks for the responses. TThanks Godfather, I didin't measure the resistance of the switch line yet, I will when I get back Wednesday time.

Thanks for the diagram Special Location. Im gonna have to do some bashing to find these jb's.

All im going to say is, what a dump?

I would be guessing its at a light fitting that has been replaced..

say a pendant ceiling rose.. Or a light fitting with a bit of connector block stuffed behind it!



Imagine all those connections on me scribble are ceiling pendants

with the three termination points...

old wires had:-

three reds together.

two black together + one side of lamp.

one black on its own + one side of lamp.

All the three reds go together so unlikely to be a problem..

but with the three black there are three combinations how you could wire it..

1/ the correct way

2/ you would end up with the switch direct across supply L&N.. (fuse pops when switch on!: O)

3/ the way how I sketched it where you loose your outgoing neutral to the rest of lights on the circuit!

IMHO

It is unlikely to be a hidden J/B or it would NEVER have worked correctly.

 

[SLIPSHOD & SLAPDASH]

To much of a co-incidence to be seperate faults (although stranger things have happened) I think there may be another jb that has been disturbed. Fault 1 is a lost live to switch and fault 2 is a lost neutral. You think you have a second live at the lights neutral, as you are getting this through the filament of a bulb elsewhere on a disconnected neutral.

 

[Apache]

consider 4 lights in a circuit as shown..

8/10 specs - your art and craft has really come on this term

2 marks off for not putting your name and age in the bottom RH corner ]

 

[SPECIAL LOCATION]

8/10 specs - your art and craft has really come on this term2 marks off for not putting your name and age in the bottom RH corner ]

sorry teach!

I will bring another apple for you tommorrow....

If mum remembers to put one in me lunch box? :_|

 

[a1]

8/10 specs - your art and craft has really come on this term2 marks off for not putting your name and age in the bottom RH corner ]

FPMSL :^O :^O:^O

 

[heathelect]

Hello Simonatlondon... welcome M8!

few point to consider here..

Re P/1

Live feed going to switch, I only get 12v.

If you get your meter and connect the one probe to live..

but leave the other probe open circuit..

your meter will probably show between 9V - 20V..

depending on if the probe is lying on the desk or being held in your hand..

{try is at home & see what you get? }

I think your 12v reading is actually from a live and to an open circuit neutral!

Re P/2

I think a light fitting has been replaced and a wire crossed when reterminatred...

e.g.

Excuse my scrappy drawing but

consider 4 lights in a circuit as shown..

between lights 'B' & 'C'

the neutral supply for lights 'C' (and then onto 'D') is connected to switched live from switch 'B'

{say a black switched live, with no red sleeve/tape.. so mistakenly thought to be neutral?}

If you are reading your voltage across live at switch 'C'

then if no bulb in 'B' there will be no neutral! thus your 12v reading.

and If NO bulb in 'B'.. lights 'C' and 'D' will not work!

If switch 'B' off and have a bulb in B.. lights 'C' and 'D' will work but dim!

If switch 'B' is ON.. then bulb 'B' will come on... but 'C' and 'D' will go off

and you will appear to have two lives at lights 'C' & 'D' and NO neutral!

Oh also no the customer is not lying?

If you followed all that....

can you now explain it to me! :^O:^O:^O:^O

Sorry..

forgot the insults...

KME's a Guinness drinker!!!

was that any good? ]

Hiya SIMONATLONDON i agree with SPECIALOCATION, to find out which wires are crossed, just find which cable is going to the switch with your multimeter,when youve found it you then know any twins left should be permanent feeds and neutrals in or out, so reconnect as usual and your light should work !!!! good luck daveGuiness Drink

 

[simonatlondon]

Thanks guys. Drinks are on me.

What a responsive lot you are. Gold stars for you aswell. Applaud Smiley

 

[Evans Electric]

Theres a wealth of advice Simon, I'll just add , Beware of customers messing with 3 plate wiring but not telling you when turn up to sort it X(