Bathroom strip light over mirror

[chambsesf]

I have recently removed a strip light prior to redecorating, and now cannot get the new one to work at all - I must be getting the wiring wrong.

I have 4 wires - red (live), black (switched live?), earth (within main grey sheathing alongside red and black), and also a separate very thick, multi-strand earth.

Can anybody please help - it's very dark in here.....

Cheers.

 

[dingbat]

If you do only have two conductors (red and black) then you won't have both a live and a switched live. What you should have is a neutral and a switched live. However, this 'extra' earth warrants investigation - it may just be an old earth wire; if it is unsheathed then this is likely, but if you have two-way switching its purpose may be more functional.

Assuming you have only one switch to operate this light and if connecting black to blue (neutral) red to brown (live) and earths to earth (ashes to ashes, etc) doesn't work then I strongly suggest you call in a pro.

(Next time you may want to make a note of what went where before you disconnect )

One last thought - if you're putting up a new fluorescent, you have installed the starter switch that came with it, haven't you? (It's a little cylindrical thingy with two prongs on one end)

 

[Lectrician]

Bathroom strip lights have a special interlock on the cover to ensure the lamp is not live with out the cover on.

If you have tried it with out the cover, fit the cover and try again.

If it still doesnt work, you may need to bend the metal tabs on the cover outwards slightly to ensure it 'catches' the ends of the lamp.

 

[dingbat]

D'oh! Must read titles, must read titles, must read titles... The only striplights I've ever installed in bathrooms have been shaver lights, but you're absolutely right, they generally do have a safety interlock.

 

[chambsesf]

Absolutely right - should have made a note of what went where when the old strip light was removed.

The new one is actually a mirror with built in lights (25w candle type), so no starter required. I have tried operating it both in 'bare-bones' format (no cover) and with the cover (actually the mirror) attached. Still no joy.

I have noticed, with the power on and touching the wires with a tester/screwdriver, the neon light inside the screwdriver illuminates on both red and black - would this happen if one wire was live and one wire was neutral?

With red to brown and black to blue, I have power inside the mirror/light, but when testing for power inside the bulbholders, I have screwdriver/tester neon illumination both on the 'base' contact and on the 'side' contact inside where the bulb screws in. Can this be right?

Thanks for all your help and replies.

 

[Lectrician]

Sounds like a lost neutral.

 

[chambsesf]

Lost neutral - sounds technical. Will I be able to find it again?

 

[plugwash]

had a simlar one to this here recently

if there are only two wires then there has to be some form of junction (junctino box ceiling rose chock box twisted wires terminal block whatever) up there in the ceiling void

the most likely explantion is the black core (which will be your neutral) has come disconnected at that junction

you really need to get up the floorboards above it so you can see whats going on

 

[chambsesf]

Right - I'll take the ceiling light off - there's loads of twisted/shared wires above the ceiling light rose. If it had come disconnected, would it be live though when I test the black wire??

Thanks again.

 

[securespark]

broken neutral?

 

[Damocles]

If you have power within the mirror light but not within the bulbholder, doesn't this suggest that the fault is between the two points you tested? bad connection on back of bulbholder? You might get an indication from a neon either from a live wire or from one not connected to anything. It may be brighter when power is on than when just floating. A neutral should be at 0V. Inserting the bulb may bring the floating live wire to 0V, because the bulb shorts the other end to neutral.

 

[ban-all-sheds]

there's loads of twisted/shared wires above the ceiling light rose.

I hope you don't mean that there are bare ends twisted together as a dangerous and unreliable method of achieving electrical connections.....

 

[Lectrician]

If the neutral is disconnected, it will rise to the potential of the live conductor through the lamps and transformer if there is one. He oly had a neon, this would glow on both live and neutral (and anything bloody else - te he).

 

[Damocles]

But a real master of the force would be able to use his light sabre, er neon screwdriver, to get some idea of whether it is a good connection to live or a floating one. Should be floating changing to live at the switched side of the switch. Or neutral changing to livel with bulb inserted.

Seriously, yes I know. not very acurate.

 

[chambsesf]

I think its probably time to call an electrician.....

Cheers chaps.