T-5 HIBAY LAMPS GLOWING

Status
Not open for further replies.

Ravenvalor

Senior Member
Hello,

I installed 6 - Tamlite 6-lamp T5 hibays in a commercial garage last May. The customer is having trouble with 13 - of the lamps glowing purple. That is approximately 1/3 of the lamps installed. Has anyone here ever experienced this type of problem before?

Thank You,
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
It may seem like not picking, but it is important:
Are they really purple (blue plus red) or are they violet (shorter wavelength than blue in the spectrum).
And is this just at the ends or the whole length of the tubes?
The light from the arc itself will be violet and UV. The normal visible light we see is the result of that light being converted by the pgosphor coating lining the tube.
If something has happened to the phosohors, the result might be purple or violet. If the whole phosphor coating has been destroyed, the result will be violet.
IMHO either the tubes are defective or they have been subjected to damaging environmental conditions or overload.
What is the temperature in the garage? If the mercury (minimum possible amount) in the tubes is not vaporizing, the output will also be affected.
The roughly 1/3 number is also suspicious if the luminaires are fed from a three phase source. :)


Tapatalk!
 
Last edited:

just the cowboy

Inactive, Email Never Verified
Location
newburgh,ny
Cold

Cold

What is the temperature in the area and check it to the ballast rating. Sometime fluorescent lamp won?t light in the cold. I have seen this in warehouse Hi-bay lighting
 

J.P.

Senior Member
Location
United States
Those came pre-lamped right?
I have put a bunch of the Atlas ones up. Even in cold shops and haven't seen this. Now I'm curious.
 

broadgage

Senior Member
Location
London, England
As a fluorescent lamp ages the mercury is used up * and this results in the lamp glowing dimly in a color variously described as purple, pink, lilac or violet.
If the amount of mecury remaining is marginal, then the lamp may work correctly when hot but not when cool, the higher temperature increases the vapour presure of the mercury.

The modern tendancy is to use the absolutely minimum amount of mercury for enviromental reasons, and defective manufacture may result in lamps without enough mercury even when new.

I would try some new lamps before looking for any complex reason.

*the mercury does not escape, but forms compounds with the other materials in the lamp, and is therefore not available for proper operation.
 

Ravenvalor

Senior Member
They did come prelamped.
Also, my sales rep at City Electric learned that there are some defective t5 lamps that have been sold in the past year. His manufacturer rep is convinced that it is the lamps. I will find out on Thursday.
Thx.

Those came pre-lamped right?
I have put a bunch of the Atlas ones up. Even in cold shops and haven't seen this. Now I'm curious.
 

Ravenvalor

Senior Member
Verdict

Verdict

We looked at the purple glowing T-5 hibays on Thursday and learned that the lamps were actually defective. City Electric was quick to give us free replacement lamps since they were only 9 - months old. Since the building is a repair facility for tractor trailers I assume the location of the hibays make them susceptible to relatively high heat during the summer. Maybe this is what caused 1/3 of the lamps to fail. This and the fact that they were manufactured defectively.

Thanks for the advice.
 

LEO2854

Esteemed Member
Location
Ma
We looked at the purple glowing T-5 hibays on Thursday and learned that the lamps were actually defective. City Electric was quick to give us free replacement lamps since they were only 9 - months old. Since the building is a repair facility for tractor trailers I assume the location of the hibays make them susceptible to relatively high heat during the summer. Maybe this is what caused 1/3 of the lamps to fail. This and the fact that they were manufactured defectively.

Thanks for the advice.



Were they Phillips lamps?
 
Status
Not open for further replies.
Top