Problem with new florescent lights

Old 07-09-02, 11:21 AM
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Unhappy Problem with new florescent lights

I recently installed florescent lights in my basement and I am having a problem with them. I installed 5 - 2’ x 4’ fixtures (34 w tubes) and 5 - 2’ x 2’ fixtures (34 w ‘U’ shaped bulbs) on a dedicated 15-amp circuit with ground fault outlet before the switches. The 10 total fixtures are wired in 4 zones with 4 switches. I have wired all fixtures in a given zone in parallel (all black wires together in each fixture, likewise with white and ground). 3 of the 4 zones work perfectly but I am having a problem with the zone that has 3 - 2’ x 2’ lights and 1 – 2’ x 4’ light. When I turn on the switch the 2’ x4’ light always lights but the 2’ x 2’ lights come on intermittently (one will come on the first time while the other 2 stay dark; a different one will come on if I turn the switch off and on again). If I play around with them long enough, I can get them to all light up together but something is not right. Since the‘U’ bulbs are 34w x 2 per fixture the circuit with 3 - 2’ x2’s and 1 – 2’ x4’ (with 4 34w bulbs) should only be drawing 68 w more than the zone with 2 – 2’ x 4’ fixtures....
The fixtures are all grounded and are on a ground fault circuit so I don’t think that’s the problem. The basement is a constant ~65 degrees so I don’t think temperature is an issue either. The fixtures are new and there is no real pattern to the non-lighting problem so I don’t think the ballasts are faulty.

Is it a matter of having too many fixtures on one switch or is there something else I should be looking for?

Thanks for your help.
Old 07-09-02, 12:05 PM
Joe Carpenter
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Try disconnecting all the fixtures in the problem zone and then reconnect them one by one checking them for proper operation afer each one is put on line. this should help you determine which fixture is causing the problem. It could also reveal any incorrect wiring that might have been done in the initial hookup.
Old 07-11-02, 07:15 AM
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OK, I looked into this problem furthur and found that all the wiring is fine and that I have good voltage at each fixture (my meter only shows ~105v but is is the same on every circuit I checked - meter is cheap an my be off) and the grounds are proper and tight.
What I did notice is that there is a sticker on the ballast that says in essence that the minimum temperature to light is 60 degrees if 34w bulbs are used and 50 degrees if 40 w bulbs are used. I have 34w bulbs in the fixtures and I assume the temperature in the basement is 62-65 degrees. Once I got all the lights to come on, I left them on for 10 minutes and when I turned them off and then back on, they all came on every time.
I returned the 34w bulbs this morning and bought 40w ones.
I will try those tonight and report my findings. I can't really imagine that this it truly the problem but I have been surprised before...
Old 07-11-02, 07:36 AM
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The problem is the the lamp wattage!!! Fluorescent lights are very picky about operating temperatures. The 40 w lamps you put in should cure the problem. Another note, you mentioned that the total wattage on the circuit is X amount. Fluorescent fixtures and the load they impose is calculated based on the ballast not the size of the lamps. Every ballast will show it's current draw on the label of the ballast. This the number that you use when calculating how much load is imposed on the circuit.

Changing the lamps to the 40W lamps will cure your problem. If you find that you still have problems and are absoluitely sure that all of your connections are correct and tight you may have to look to a low temperature ballast. These are more expensive, they are normally used where fluorescent lighting is used in large walk in coolers or freezers. Like a beer distributor or food distributor.
Old 07-11-02, 05:45 PM
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I would not reccomend putting basement lighting on a gfci.
Not required for basement lighting.

Good Luck
Old 07-12-02, 07:40 AM
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GFI is not required for any type of inside residential lighting. The only concern with tieing lighting and receptacles together on a GFI circuit is the nuisance tripping issue the lights can cause especially with GFI protection.
I don't think this is even a factor since you said nothing about it in your post.
You never wrote back to let us know if the new tubes corrected your problem.
Old 07-12-02, 12:31 PM
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The ballasts say they use ~.67 Amp with 34 w bulbs and ~.77 Amp with 40 w bulbs.... (P=I squared x R)
I installed all the 40 w bulbs and it looks like they are going to work fine... Naturally, I buy 10 bulbs and only 9 of them will light. I have one that is dead, won't flicker or anything. Swapped it out in several fixtures but it killed each one I tried it in. Got the new one in the car - I am sure the problem is solved.
Thanks for the help!!!!

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