# T5 8 ft fixtures weatherproof



## Zaped (Jul 6, 2008)

New 8 ft weatherproof T5 4 bulb fixtures. Row of 10 such fixtures. why would four(4) of these fixtures lose two bulbs each (i.e., two bulbs won't burn, that is, two bulbs on same side of each fixture of these four fixtures. 8 bulbs total won't burn.)? What would cause this ? What would remedy this ?


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## JM2 (Aug 5, 2011)

Howdy!
Often the newer electronic ballasts for T-5's are feeding 2-lamps but sometimes they are built for 4-lamps. Check this out first. Then use your voltage sensor/detector (chirp stick) to see of there is voltage at the leads from the ballast for each of the leads heading to the lamps. If one of the leads is dead, then bad ballasts. More likely, the leads are good and the likely problem with the way the wires are landed (plugged-into) in the sockets (if they were routed properly in the first place at the factory). Since you have so many this way, it is likely a manufacturing/assembly flaw. 
Of course, verify that ballast rating and your delivered voltage are the same, etc.
What checking have you done thus far? Happened at initial lighting? Happened over short "burn-in" time?
Good luck, my friend!


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## JM2 (Aug 5, 2011)

Just had another thought - are the lamps fully/properly seated in the sockets?

And another... Were the lamps handled roughly? The fillaments may be damaged - a simple continuity check across the two pins at each end should verify "good" filaments.

You're looking for a "same" failure reason for a "batch" of product at a "common installation" time, obviously. It might be as simple as a loose wire-nut connection at the supply connection caused by the same installer not catching this on a two-lamp kind of ballast arrangement. The ballast check should guide you on where the power is stopping on it's way to do it's work....


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## BBQ (Nov 16, 2010)

Did you check that the sockets are wired correctly?


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## JM2 (Aug 5, 2011)

Last thought: If there is a wiring problem on the lamp side of the ballasts, the wiring diagram for them is shown graphically & schematically on the label/cover of the ballast itself.
Lemmieno what you find, okay?


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## jwjrw (Jan 14, 2010)

BBQ said:


> Did you check that the sockets are wired correctly?


Wouldn't be the first time. I have ran across that on new fixtures a few times.


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