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Need an electrical diagnosis.

Good evening,

I'm having all manner of trouble figureing out what's wrong with my terrarium lights. I just built the hood and installed two fluorescent light fixtures that both hold 2 24" tubes for a total of four. They are wired correctly to my power cord. I bought some cord about 12 feet in length. I don't remember the guage, but it wasn't the lightest they had at the Ace Hardware. I also bought a plug (more on that in a bit), and on/off switch which I carefully installed on the cord. They are both rated at 15 amps. Oddly, the plug is not polarized.

The problem is that the lights are very difficult starters. Once they're on, they seem fine. But starting them is very hard. They seem to start to glow orange on the ends as soon as you turn them on. Sometimes they'll pop on after a couple of seconds. Sometimes just two of them do (and which two is random). More often, none of them start. Sometimes if I touch one of them, they'll all come on or two will. Usually they don't. If I just let them sit there, it doesn't seem to go anywhere, and the orange glow even starts to fade a bit. I've waited as long as a minute, and they never go on. If they don't go on right away, they won't until I touch them or fiddle a bit (maybe.)

These symptoms have persisted at home and at work where the terrarium is. Although I can get the lights on, it pretty much precludes using a timer, which is necessary to get the plants enough light. I just left them on tonight since they didn't get much light today with all the experimenting.

The odd thing is that all four lights are acting identically, so it isn't a bulb, a starter, or a ballast, at least in all likelihood. And it's the same whether warm or cold. I'm pretty much open to suggestions at this point.

Caplsock
 
hmm each light fixture was prewired going from the ballast to the endcaps?

I really can't imagine it is the wire or plug. Did you check the light bulbs and see if it says rapid start on them?

Tony
 
I did not notice whether it said that on the bulb, but I'm holding the sleeve here at home, and it doesn't mention "rapid start" on it. I have the Philips Cool White and the Philips Plant & Aquarium "Alto". They were purchased from Home Depot at the same time I bought the fixtures. And the only other choice was Warm White.

Capslock
 
Guess what caps, I'm an electrician.

It could be a number of things.

1. You mentioned that the plug is not polarized, Does that mean that there is no ground? If not trying giving it a ground and see what happens.

2. Make sure you have the hot and neutral wire in the correct terminal. The hot should be a gold color screw and the neutral should be silver. Plug in the wall should have two vertical slots. One should be longer than the other. The long one is the neutral and the short one is the hot. Make sure that stays the same all the way to the light. In the light you should have a black and a white wire. Black is hot and white is neutral.

3. Make sure the wires from the ballats to the end caps are making good connections.

4. This is going to be hard to explain. On some lights the wires from the ballast to the end caps have to be in the correct slot on the end cap. Some lights this don't really matter. Look on the ballast it should have a diagram that tells you what wire goes where. Follow that diagram.

5. Make sure you have the correct bulb for that ballast.

6. Make sure all your connections are tight.

7. Make sure the bulb is making a good connection.

From what you are describing it sounds like there is a loose conection somewhere, I'd say it's either the bulbs or the end caps.

If you still can't fix it, send me a pm and I'll give you my phone number and i'll see if I can help you that way.
 
Wow, thanks Ozzy. This is going to be difficult, I'm afraid.

1. By polarize, I mean the two vertical slots on the plug are the same size, one is not longer than the other. This makes it impossible to know which one is neutral and which is hot. We reversed the plug to see, and the behavior persisted.

2. see above
3. I will check again tomorrow morning at the office, where the tank is.
4. I saw and followed the diagram, but will double check tomorrow.
5, 6, 7. Yup. Did for a couple hours of fiddling today. Will again tomorrow.
smile.gif
Seems if there was a loose connection that would respond more to jostling it. The bulbs will "pop" on when I just touch them the slightest bit, but do nothing if I give them more nudging and tugging. It seems like it's just on the brink of lighting the tubes, but just doesn't quite get there.

I'll pm you tomorrow if nothing turns up. Thanks for your help! At some point here, I'm going to give up and see if some compact fluorescent fixtures will fit in my homemade hood.

Capslock
 
Bulbs will do that when they are getting old, but you said they were new right?

It sounds like the bulbs are not making contact for some reason.
 
Brand spankin new bulbs. And they glow orange when you turn it on, so they're making SOME contact. Sigh.

Capslock
 
Problem Solved! At least I think so. I mentioned before that I was using an ungrounded power cord. In talking to the guy at Home Depot, he said that you should always ground fixtures with magnetic ballasts. So, I replaced the cord with a grounded one, and it seems to work just fine now. Hopefully, this solves the issue, although it meant I had to buy a new timer to allow for the three-pronged plug. Thanks everyone for your help! I would have gone insane if I couldn't run this by people like I can here.

Capslock
 
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