fluorescent luminaries are defective to fix the problem

[JJWalecka]

I have a question regarding an issue with 480 volt two t5 tube fluorescent luminaries. We installed over 500 three ballast fluorescent luminaries manufactured from Mexico ( so you know there quality ). The fluorescent luminaries are defective. To fix the problem the manufacture is paying us to put a "Ferret" on the yellow wire that is out of each ballast. I was told it corrects the induction. One of the "Ferrets" was broken in half. I observed that it is a hollow, cylinder piece of what looks like Lead. It is not lead. I wish I had more information to give.
Is anyone familiar with how it works? Any help would be appreciated.
Thank you for your time and effort.

Justin W

 

[rattus]

Re: fluorescent luminaries are defective to fix the problem

Justin, the word is "ferrite", and you are describing a "ferrite core" which is donut shaped. It is made from iron (ferro) powder and some sort of binder. When you slip one of these over a wire, you increase the inductance of said wire which tends to block the higher frequencies with hardly any effect on 60 Herz.

These cores are widely used in small inductors and transformers and ages ago tiny ferrite cores were used in computer memories. Some of the old heads still talk of "core memories".

If you open up a light dimmer, you might find one of these cores wound with several turns of wire for noise suppression.

 

[JJWalecka]

Re: fluorescent luminaries are defective to fix the problem

Thank you very much Rattus.


Justin W.

 

[mdshunk]

Re: fluorescent luminaries are defective to fix the problem

Justin, I'm curious what the nature of the defect was? I saw a display of T5 lay-ins at my local supply house, and they said they wouldn't sell them to anyone because they took so long to fully illuminate. Was this your issue?

 

[hurk27]

Re: fluorescent luminaries are defective to fix the problem

ferrite core's are placed on the output conductor's and sometimes the power supply conductors to stop RFI leaking out as per FCC regulation (Part 15). They have no effect on the operation of the fixture. They are also used to stop it from getting in other types of electronics also.

[ May 09, 2005, 02:55 AM: Message edited by: hurk27 ]

 

[LarryFine]

Re: fluorescent luminaries are defective to fix the problem

They're functionally identical to the 'chokes' placed on computer cables; those cylindrical plastic-coated bulges near one end.

 

[rick hart]

Re: fluorescent luminaries are defective to fix the problem

I thought I was going to find out a new way of troubleshooting light fixtures using a rodent!!!!
You know, I'm almost disappointed.
Reminds me of a boss that took pride in having a father that served in the battle of IOWA Jima in a company announcement.
Sometime spell check is a bad thing.

 

[JJWalecka]

Re: fluorescent luminaries are defective to fix the problem

Hurk27 and LarryFine thank you for your input. Mdshunk I was told that the luminaires were defective. "They don't work after a period of time", was the basic explanation that I received. I'm not exactly sure of the nature of defect. I will try to find more info on the issue. Apparently there are three stores in New England and three in Maryland to be fixed by the company I'm employed by, that I'm aware of. Rick Hart !

Justin W.

 

[hurk27]

Re: fluorescent luminaries are defective to fix the problem

They don't work after a period of time

That is a very open statement to tell you what's wrong?
I can't see that installing the ferrite cores will help?

 

[JJWalecka]

Re: fluorescent luminaries are defective to fix the problem

Hurk27 It is a very vague description regarding the defect. Unfortunately I currently do not have any more information to provide. We are installing two ferrites on one of the two yellow wires out of the ballast. I don't understand how two ferrites on one of the two would correct the problem. I did not see the spec that was given from the manufacture. I am not the foreman on this job. I appreciate your feedback. Thank you


Justin W

 

[JJWalecka]

Re: fluorescent luminaries are defective to fix the problem

I have observed that the ends of the T5 lamps are begining to blacken. The luminaries and lamps are only a few months old.
Is this common for the lamps to blacken in that short of time?
Could that be due to the defect that the Ferrite would correct?
Thank you
Justin W

 

[hurk27]

Re: fluorescent luminaries are defective to fix the problem

It could be that the ballast is producing harmonics on the output and are causing the premature failure of lamps. The ferrite core's will limit the higher frequency of the harmonic's but still seem's like a band aid. Electronic ballast produce an output frequency of about 15khz the harmonics on the 5th order would be around 240khz so maybe this is causing the blackening of the lamps?

 

[rick hart]

Re: fluorescent luminaries are defective to fix the problem

Just a hunch here-
T5 is new energy efficient technology.They cost less to operate than T8 but, so far, I haven't made the life cycle cost show they are cheaper in the long run.

The hunch is: this is part of the research and development of T5 technology. After a few years of paying to make it work by trial and error, the manufactures will produce cost effective T5 fixtures.
Until then........

 

[JJWalecka]

Re: fluorescent luminaries are defective to fix the problem

Hurk27 and Rick Hart thank you for your time.


Justin W