Flurescent lighting problem

[collumgary]

Hi, I have a flurescent lighting problem if anyone can help?

when i test between live and earth I get 240V, but when I test between live and neutral I 50V. wall light fed from the same live connection works.

I disconnected the live and neutral from the light and got 240V between them.

Dose this volt drop have anything to do with ballast or cappacitor failure?.

Also flurescent next door has also fail (24hr latter) and seems to have the same problem, 50V between live and neutral.

This is wired on the same circuit down stream, could the first light failing affect the scond?.

The first light is switched by a dimmer, can this cause failure due to wrong operating voltage?.

Thanks for any help.

 

[Darkwood]

Sounds like you lost a neutral, where ever the neutral is taken from up stream is where you need to look if it isnt a loose connection in the fitting

 

[collumgary]

why am I getting 240V between live and neutral when disconected from fitting, and why is incandecent wall fitting working and reading 240V?.

 

[collumgary]

Incandescent fitting fed from the same live as fitting and neutrals are connected together.

 

[Darkwood]

be careful in what you think you are reading as you may effectively create a false neutral through the ballasts of the other fittings when you test, i still think neutral missing may be your problem, i suggest a fly lead from a good neutral point to the fitting to see if this cures it then you know for deffo its missing then.

 

[acvc]

Are these fluorescents really dimmable, according to the manufacturer's installation instructions? Are they T8s or T5s, or compact???

 

[nickblake]

Not seeing the installation its difficult to give a good fault diagnosis , but ill try are RCD's in circuit ,I agree with darkwood when you get 50v readings it tends to be a neutral fault , so start at the the begining ,test Ze at the board ,then do an R1R2 test to the point of the fitting the do an RnR2 test (neutral and cpc joined at the board Remove from terminals to do this) this will confirm polarity of the circuit and that the continuity of the conductors are intact then do an IR test as you would to confirm there are no faults on the circuit , now the reason for doing those tests 1 if you have a neutral supply fault you could end up with false readings 2 if you have a neutral fault where the neutral has broken ,but there is a earth to neutral fault down stream of the neutral break then the lights will work ok there and the readings will read ok (unless you have an RCD in circuit then it will trip ) check these things and eliminate them

Nick