Fluorescent lamp repair questions

[Deleted member 18243]

I have to repair a 2 x 58w fluorescent fitting in which only one tube works.

I am familiar with fittings that use a ballast, and have repaired several of these (by replacing the ballast).

However this fitting is different: it has two chokes, two starters and one capacitor. I have tried replacing both tubes and both starters but still only the one tube lights.

So my questions are:

What kind of fluorescent fitting is this?

How does it work?

What should I try next to fix it?

NB The chokes are Tridonic Atco EC58 A502.

Thanks.

 

[tim west]

Have you checked the choke, continuity of the wiring and lampholders?

 

[Spark123]

How is the capacitor connected in? Is it across the supply terminals or is it in series with one of the chokes?

 

[RF Lighting]

So my questions are:

What kind of fluorescent fitting is this?

A twin fluorescent

How does it work?

The same as two singles do

What should I try next to fix it?

http://www.tlc-direct.co.uk/Products/TNPP258.html

 

[Spark123]

it could be a lead lag fluorescent fitting which is why I asked about the capacitors connections.

 

[RF Lighting]

You must have posted at the same time as me. Never saw your post.

You are quite right though, could be lead lag.

OP, what sort of location was this fitting in?

 

[Steve]

You know what I hate?

Where theres a row of twin fittings, butted backtoback, and one in the middle has been changed and the caps come out at different angles to the rest.

Looks so naff.

 

[Spark123]

Not as bad as having a row of the old type which you need to pull the end cap back to fit the tube in fitted end to end though

 

[Taylortwocities]

Back to the post. I had the same problem with about half a dozen twin fittings. In each case (bar one) it was the half of the fitting that had the cap in series with the choke that was not working. Maybe someone had meggered the lighting circuit or perhaps they were cr*p caps...

The cap is there as a lead/lag to reduce strobe effect in workshops, it also reduces start up and running current. Power factor nearer 1.

As a test I just shorted out the cap and the fittings worked/ I then bought some replacements.

TLC used to do them but I think they are now discontinued (Fitzgerald RIP).

I sourced some 4.7µF motor start caps 440V wkg - it did the trick.

 

[RF Lighting]

As a test I just shorted out the cap and the fittings worked

Just don't try that if they are standard fluorescents, and it's a smoothing capacitor across the supply

 

[dannyboi2003]

What do you mean(Fitzgerald RIP) TTC? They are still going strong far as I'm aware? http://www.flg.co.uk/

 

[333rocky333]

What do you mean(Fitzgerald RIP) TTC? They are still going strong far as I'm aware? http://www.flg.co.uk/[/QUOTE]


http://www.smeweb.com/economy/news/fitzgerald-lighting-limited-in-administration-120803.html

 

[Taylortwocities]

Phew, thanks Rocky. For amoment there i thought that i was losing it...

BTW TLC still have replacement 5µF caps available.

 

[Deleted member 18243]

Many thanks to all who have replied.

OP, what sort of location was this fitting in?

It is in a large open-plan office and is one of about about 30 similar fluorescent fittings. Some are of this type but some are ballast-types. All have diffusers.

How is the capacitor connected in? Is it across the supply terminals or is it in series with one of the chokes?

It is connected directly across the supply terminals.

Have you checked the choke, continuity of the wiring and lampholders?

I haven't checked continuity yet, I shall do this in the morning. (I only get a short amount of time in the morning to do these jobs before the regular staff come in). I don't know how to check the choke.

If I find that continuity is OK then surely it must be one of the chokes, because I will have tested everything else. Would I need to replace just the choke that is connected to the non-working tube or would both chokes need changing?

 

[Spark123]

Are you competent to be doing this work? An office is a place of work hence the Electricity at Work Regulations apply.