Fluoresecent tubes only work intermittantly

[garyeuph]

Hi,

I recently replaced two very old fluorescent tube fittings with modern variety (much thinner) - the old ones always 'hummed'. These work fine, however I often need to switch the light switch on a few times to get them to start, and sometimes only one of the will start.

Do they need a certain voltage to work? I have a feeling that they may have initially been wired in series, or that there are other lights taken in series from them.

I would appreciate any thoughts on this

many thanks

Gary

 

[Lectrician]

Where are they fitted?

What other lights operate from the same switch?

Is it one fitting, or two singles?

did you replace the fitting or just the tubes?

 

[garyeuph]

In the kitchen, they are the only lights from the switch and are two separate single fittings. I replaced the fittings, not just the tubes.

My electical screwdriver barely lights up when applied to the live circuit, but is quite live at the wall switch, if that helps?

 

[Lectrician]

Can you describe the wiring inside each fitting (the cables from the ceiling, and how they are connected?)

 

[breezer]

have you changed the "starter" see here

 

[garyeuph]

They do not have starters.

One of the lights is a simple spur off the other (or appears to be)

The other is a bit of a mess - I just resused the existing connections. There are several red wires all fed together into a terminal block, there are foor black wires into the terminal block that ffeds the light, similarly there are two red wires into the terminal block that feeds the light, plus a whole hosy of earth connections, all linked together

 

[breezer]

pic would be nice

 

[garyeuph]

I would if I could, but no digi camera!

I guess I can live with it, it just seems bizzarre. When I decorate the upstairs room I will lift the floorboards and have a good look at what was done before I got the house.

Thanks for listening anyway

Gary

 

[breezer]

we tried, but how about some nice new lights instead, may be quicker? but do not my signature (are you sure they dont have a starter, they are really small and stcik out the side of the light)

 

[garyeuph]

No definately no starter, and it confirms this in the instructions (says this has an electronic ballast and does not require a starter switch). They are nice new lights, I only bought them 1 week ago from B&Q

Eterna Model EB1X58 www.eterna-lighting.co.uk

 

[uselessFCUK]

Is Live to L and Neutral to N? This Q not meant to be offensive.
Possibly defective capacitor.

I would discourage the use of tester screwdrivers as opposed to a DMM. These testers work from 70volts up therefore if you have a voltage drop in the line to the luminaire you can't really tell. As you said it barely lights. Check the voltage at the luminaire with a meter. You may have a poor connection at the switch or in a j/b somewhere.

If not, take the fitting back to B&Q and say its goosed; get another.

 

[garyeuph]

No offence! I always have fun in matching red to brown and blue to black -- why did they change the standard?

I will borrow a DMM on Sun hopefully and get a better idea; if there is a voltage drop I will have to sort it out eventually.

For connections, would I be better off with 'crimp' fittings rather than 'screwed' terminal blocks? I suppose I can test this with the DMM also, if the voltage drops off over the connection that will be my problem.

Am failry sure the B&Q fittings are OK, as 90% of the time they are fine, it is just occasionally they refues to light up, or only one of them does

 

[felix]

Your neon driver has told you what you needed to know. You just need to interpret the results correctly. If it lights up bright at one end of a wire but only dim at the other end, that wire is broken or, more likely in your case, you're looking at the ends of two different wires.

Check the switch first. What coloured wires are in it? Red and black is normal. Do you get a bright neon on the red one at all times but on the black one only when the switch is on? This would be normal.

Now go to the ceiling end. Are you sure the lights are connected to a wire from that switch? I ask that because you say they're connected to red wires.

Have any of your other lights started to misbehave since you did this job?

 

[securespark]

Two-way/ intermediate switching fault?

Wired in series somehow? Wiring mixed up so that fitting is in series some of the time.

 

[supersparks]

Your neon driver has told you what you needed to know. You just need to interpret the results correctly. If it lights up bright at one end of a wire but only dim at the other end, that wire is broken

one little tiny thing.....

unless he is very tall the lightswitch and light are likly to be at different heights and one is likly to require something to stand on.....

like a wooden chair for example

hell even alu steps have plastic or rubber feet......

so it being dimmer at the fitting end really dosnt say much....

get your dmm and use that mate