T5HO light problems

[scottym]

Merry Christmas everyone,

I recently installed some 4 bulb T5HO light fixtures in my garage. One of the light fixtures will only light 2 of the 4 bulbs. All bulbs are brand new and the bulbs that didn't turn on were tried in another fixture to ensure that the bulbs are good. The light fixtures are made by Cooper and the ballasts run off of 120v or 277v. Does anyone know what could cause this.

Thanks.

 

[mtne]

The first quick check would be to make sure the ballast wires to the tombstones are all in and secure. Until I've check that it's not the lamp or a loose wire connection, I don't worry about the ballast.

 

[Charles (in GA)]

I have an idea. If the ballast is one of these...............

Then it has, as you can see in the diagram, two inputs. One is the main input, and the other is a secondary input. You could use separate switches so that you turn on one to power the primary and juice to the secondary switch and then when you turn it on, the other two light up.

If you want all four to light and not fool with two switches, you wirenut the incoming hot and BOTH OF THESE wires (the black and the red/black) together. This is what I did when I wired up my four tube 8 ft T5HO over my workbench.

http://www.garagejournal.com/forum/showthread.php?t=118182

What might have happened is that the red/black wire got missed and not wire nutted together with the incoming hot and the black to the ballast, OR..... it did get wire nutted but not stripped and thus no connection due to the insulation, OR.... it just barely got caught and looks good but is not a good connection.

Just a guess..................

Charles

 

[tfi racing]

I just installled 178 T5HO fixtures on a project last week,out of all of them I had five that would only light two of the four lamps...Two were loose/missing connections at the tombstones,the other three I tried lamps,ballasts,checked all the connections and they would still not light.I suspect an internal fault with the tombstones,but I had no spare parts, time ran out and I had a flight to Cancun to catch...

 

[scottym]

Hey guys thanks for all of the help. I will go out and check the connections at the tombstones.