MH Ballast Gone Bad???

[tygger]

When I first got into s/w, I had no idea what was good or bad. I ended spending a lot of money on a Coralvue 48" fixture for my 72g tank. It includes 2 250w MH HQI (DE) bulbs, 2 250w MH Electronic ballasts and 4 24w PC actinics.

 

It's been awhile, but the problems are back. One of my Coralvue 250w MH DE ballast doesn't start the bulb. How can i tell if I need a new ballast or if I just don't have enough "juice" running from the outlet to the ballast?

 

Secondly, one of the 24w PC actinics is now having problems firing up. It flickers for a while before it finally fires up. Is this a sign of a bad bulb, fluorescent starter or ballast?

 

 

** note **

 

I just tried firing the "bad" bulb with the known working ballast and it didn't fire up. 10 minutes later, I put the known working ballast back on the "good" bulb and it started it up. Awhile back, I've tried swapping the bulbs from the side that does work to the other and it doesn't make a difference.

 

Edited January 23, 2007 by tygger

[Guest tgallo]

i think its a bad bulb , how old is it and im not sure if the power compactsa in that fixture have a seperate starter.

 

the power from your outlet to the ballast is fine, if not, none of them would work.

[Coral Hind]

You didn't mention how old the bulbs or ballasts are. I would try changing them out first. Borrow from a club member if you need to for testing. Since it is an electronic ballast try unplugging the ballast for seven minutes to reset the safety built in to the unit. It protects against the capacitors causing a massage voltage spike. Also check and see if the unit has a fuse on it. Also DE bulbs are more stubborn to light then SE ones. Make sure the cord from the ballast to the bulb is not longer then 8 feet. The ballast should have a two year warrenty.

 

Is there a grounded reflector above the PCs? Flourescents may not fire if there is not a grounded piece of metal/reflector above them. It helps the arc flow through the tube. If the bulb only lights when you touch it then it needs the grounding.

[tygger]

i think its a bad bulb , how old is it and im not sure if the power compactsa in that fixture have a seperate starter.

 

the power from your outlet to the ballast is fine, if not, none of them would work.

 

 

I bought the fixture over a year before I actually used it. Overall, the fixture is about 2.5 yrs old, but its only been in use for about 1 yr.

 

The fixture is enclosed, meaning the bottom has a glass "splash" shield so I'd have to take that off to see there is a separate starter (dont remember).

 

So if the power was a problem, none of them would work? That's good to know. I have two bulbs in the fixture. I set one to come on 30 min before the other. Usually, its the second one that has a problem starting so I wasn't sure if the one that was already on was "stealing" all the power.

 

Thanks!

Edited January 23, 2007 by tygger

[tygger]

You didn't mention how old the bulbs or ballasts are. I would try changing them out first. Borrow from a club member if you need to for testing. Since it is an electronic ballast try unplugging the ballast for seven minutes to reset the safety built in to the unit. It protects against the capacitors causing a massage voltage spike. Also check and see if the unit has a fuse on it. Also DE bulbs are more stubborn to light then SE ones. Make sure the cord from the ballast to the bulb is not longer then 8 feet. The ballast should have a two year warrenty.

 

Is there a grounded reflector above the PCs? Flourescents may not fire if there is not a grounded piece of metal/reflector above them. It helps the arc flow through the tube. If the bulb only lights when you touch it then it needs the grounding.

 

The bulb and ballast are about 2.5yrs old with about 1yr usage on them. I forgot to mention... I've had this problem from the first month I started using it. The problem comes and goes. At first, it was just an annoyance, but now I have corals in the tank that depend on the lighting.

 

When I get home today, if the light isn't working... I'll swap that bulb with the one that is working.

 

I've tried unplugging the ballast for well over 15 minutes. Doesn't seem to to help. Yesterday when I posted this, I swapped the ballast from the lit bulb to the other bulb and still nothing. When I swapped it back, the original bulb lit again.

 

I'll need to check the cord length again, but I'm possitive its exactly 8 feet now. Coralvue advised me to shorten the length because what they provided was about 15 feet! This was over 6 months ago when they were originally helping me troubleshoot.

 

There are reflectors above the PCs and I'd assume they're grounded since they're screwed into the fixture. 3 of the 4 separate PCs work. Only one is having this flicker problem. What should I do here?

 

 

Thanks!

[Coral Hind]

3 of the 4 separate PCs work. Only one is having this flicker problem. What should I do here?

Thanks!

 

Eliminate if it is the bulb or a ballast/wiring problem. Put the problem bulb in the other three sockets and see if it lights. If it does then the bulb is good, if not then get a new one. Put the good bulbs in the socket that flickers and see if it lights. If not then check the socket, some times the fingers in the socket do not grab the bulb pins securely and they arc. This causes the end sockets to burn up/stop working. You will usually see some black coloring around the holes of the socket or on the pins of the bulb. If it looks good and the wires look good then it is propably the ballast.

[tygger]

I came home today and all the lights were working so I didn't want to test risking that they won't come back on again. The corals need all the light they can get right now...

 

Thanks for the suggestions. Keep them coming if you have any other ideas and i'll test them all at once when the lights don't work or on the weekend when I can mess with them before the timer sets them on.