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Topic Title: mystery fault on 4ft fl tube
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Created On: 19 April 2013 04:01 PM
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 19 April 2013 04:01 PM
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skup53

Posts: 39
Joined: 10 June 2011

Any ideas apprectiated based on experience. Fitted 4ft tube in garden shed. It flickers at the ends , fitting changed, same problem all tests ok 238 volts earth zs etc all well inside limits. Changed to an electronic fl fitting no flicker at the ends but middle of tube is dimmed with visible rings running in one direction. This fitting runs fine at home with 220 volts.
I think this maybe supply harmonics or similar. I still need to try the fitting inside the house to check if its the same insidethehouse. Supply to shed is via rcd fcu and swa with all armour earthed, nothing else in shed running ? Anyone has anything similar?
 19 April 2013 04:15 PM
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Jaymack

Posts: 4583
Joined: 07 April 2004

Originally posted by: skup53
Any ideas apprectiated based on experience. Fitted 4ft tube in garden shed. It flickers at the ends

It could be a choke or starter problem when there is no surge, it needs HV to strike across the length of the lamp.

Regards
 19 April 2013 04:21 PM
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AJJewsbury

Posts: 11251
Joined: 13 August 2003

It flickers at the ends

As in lit OK along it's length, but a bit of a flicker (extra light) at the ends? If so, that's not uncommon with brand new tubes in switch-start fittings - it tends to die down after a few days running.

middle of tube is dimmed with visible rings running in one direction

I've no explanation, but I have seen that before - on a bus! - presumably it was DC powered so maybe interference (from the engine systems) is a possibility.

- Andy.
 19 April 2013 04:28 PM
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Legh

Posts: 3472
Joined: 17 December 2004

I installed two fluorescent fittings in a greenhouse, one with an electronic starter and one with a standard ballast and capacitor. The one with the new electronic starter had the running rings the older one didn't.
I haven;t a clue either why the electronic circuitry should cause that effect.

Legh

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 19 April 2013 05:45 PM
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mikejumper

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Originally posted by: skup53
........ all tests ok 238 volts........

Did you check the voltage with the tube switched on?
 19 April 2013 06:12 PM
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normcall

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Temperature can cause problems with these fittings. A lot don''t appreciate starting when chilly.

-------------------------
Norman
 19 April 2013 06:22 PM
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skup53

Posts: 39
Joined: 10 June 2011

Yes checked the voltage before and after only changed 1 volt
 19 April 2013 06:36 PM
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prophet

Posts: 186
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How long did you leave it to run? Have seen them do what you describe on cold days, but after a few mins they've come right

Tom
 19 April 2013 07:06 PM
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broadgage

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Almost certainly due to the lamp being cold, or new, or both.
Should improve with use.
Most electronic ballasts do not run the lamp at full power which increases cold related problems.
 19 April 2013 07:12 PM
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mikejumper

Posts: 1701
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Originally posted by: broadgage

Almost certainly due to the lamp being cold, or new, or both.

Should improve with use.

But accoding to the OP it runs fine at home.
 20 April 2013 06:33 AM
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normcall

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No doubt after getting warm and cosy, wouldn't you?

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Norman
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