Lights in two Rooms just stopped

[ChuckUK]

Hi,

I have weird electrical problem in two rooms on the second floor. The on suite bathroom and bedroom have no working lights. I have checked for power on the radial circuit and found the ceiling rose has power and so does the bathroom lights have power. The weird thing is the (although they both do this) if I turn on the bedroom light the power to the rose goes !!, the light is just a switched live connection using two reds. I have put a meter on the ceiling rose circuit to the live and neutral and get 240v, if I turn on the lights I get nothing !!

Can anyone explain this, the rest of the circuit is fine just these two rooms.

Thanks in advance.

 

[ChuckUK]

I have pulled out all the bulbs to the lights and found that I get 240v to the light fighting (if switched on), once I put a bulb back in bathroom or bedroom the power to the fighting goes.

 

[RMS]

Have you tried a different bulb and proved it works. Maybe the contacts in your pendant are not making with the bulb. What are you testing the power with. You may have a break in your neutral. You will get voltage(230v) live to earth, nothing between live to neutral and voltage (230v) neutral to earth.

 

[ChuckUK]

The bulbs are all fine I have checked them. I have used a multimeter to measure 240v accross live and neutral, although I get more like 220v.

The weird thing is how can i get 240v at the ceiling off the neutral and live (this is the non switched live) then i flick the light switch and I loose power.[/img]

 

[Steve]

Have you actually altered the wiring at all?

 

[RMS]

Okay, switch the light on and measure for voltage across neutral and earth??

 

[ChuckUK]

Nope not changed a thing, turned on the bathroom lights, (they are the 12v jobbies with each one having a inline transformer) they came on then went out, now I have no bathroom lights, over sink light, extractor fan and bedroom light.

All other lights on the ring are fine. Initially I though the ring had tripped, I have since turned off/on the ring and checked voltage at the different light points etc and they have power.

Take the extractor fan as the simplist of my weird problems. It turns on/off outiside the bathroom but also has a pullcoord on it. With the pullcoord in the off position but the wall switch in the on position I have power going into the extractor (there is a 3amp fuse next to it that I have measured from). I pull the coord and the power goes !!! the on/off switch is left in the same postion.

 

[ChuckUK]

Neutral and Earth with switch off nothing, on, I get about 230v.

 

[RMS]

You have a break in the neutral conductor within the wiring of the bed/bathroom area or near. Hence the live cannot flow back through neutral causing the circuirt to be incomplete and leaving full 230v present on the neutral.

 

[ChuckUK]

ok,

so if all the other rooms are working and off one of those rooms the ring continues in say the bathroom first then are we saying the netrual has broken after that? and if so then if the bedroom continues in the ring after the bathroom this would explain why this is working also?

Where is the most likely place for the break? as I haven't touched anything could I use a simply continuity test along each segment?

I also assume if this is broken then it must be between the last working light and the first one that isn't working?

 

[RMS]

Check all connections after the last working light, joint for low voltage lights, or the supply may loop into the switch and the fan isolator. If this fails then you can carry out a continuity test between legs incase of any breaks in the cable where its is not exposed.

Let me know how you get on.

 

[ChuckUK]

Thanks for that, I'll start looking tomorrow.

Still can't get my head around how the neutral could break, the house is only 4yrs old.

 

[RF Lighting]

It probably will not have actually broken in the physical sense, (i.e. snapped) but more likely there will be a loose joint or one that has become corroded or burnt. The term 'a broken neutral' refers to a break in the continuity from the lights to the consumer unit.

 

[securespark]

Yeah, it's most likely a poor connection at a JB or rose.

I often find this. Customer complains of one or two (or three or four, but not the whole circuit) lights going down, and I find a loose connection in a terminal. Often it's at a rose where the bare conductor has not quite made the screw, but is touching the terminal. Sometimes the conductor has been inserted correctly, but the screw is loose.

 

[ChuckUK]

Fixed thanx guys.

I found the fan/bathroom lights in the 2nd bedroom had the ring going through the wall switch. The neutral that continued out of the switch to the bathroom/bedroom that had no power was no connected properly.