Can I wire two lamps with a four lamps ballast?

[zappy]

All we have available are these four lamp T5 ballast. I was wondering if I could wire two lamps with it or do I need a two lamp ballast. Thank you for your help.

 

[Little Bill]

All we have available are these four lamp T5 ballast. I was wondering if I could wire two lamps with it or do I need a two lamp ballast. Thank you for your help.

The ballast will tell you the number of lamps and how to wire them.

 

[zappy]

The ballast will tell you the number of lamps and how to wire them.

Yes, but it doesn't show if you could wire it for two lamps so I guess you can't.

 

[4-20mA]

Yes, but it doesn't show if you could wire it for two lamps so I guess you can't.

Huh? Looks like you could just use half of it and cap off what you don't use.... hopefully you're only asking for "code purposes"... is it against code? I have no idea, but this isn't exactly a brainteaser, wire-wise...

 

[zappy]

Huh? Looks like you could just use half of it and cap off what you don't use.... hopefully you're only asking for "code purposes"... is it against code? I have no idea, but this isn't exactly a brainteaser, wire-wise...

I just assumed, because it didn't show two lamps but I did what you said. Thank you.

 

[zappy]

Here's the old one. Is there anyway to test this with a meter to see if this ballast is bad?

 

[4-20mA]

Here's the old one. Is there anyway to test this with a meter to see if this ballast is bad?

I'm not sure how to test one per se, never tried. I have read that some ballasts can produce over 600v and a lot of meters will not like that. Just from a quick Google search.
How's it smell? Usually, one can tell if they're fried like that.

 

[Little Bill]

Known good lamps, wiring correct, power present, lamps don't light = bad ballast

Ballast usually list the number of lamp combinations and the wiring diagram, if you try to wire them for more or less lamps than it's designed for, you either shorten the life of the ballast or the lamps.

 

[kec]

All we have available are these four lamp T5 ballast. I was wondering if I could wire two lamps with it or do I need a two lamp ballast. Thank you for your help.

Of course, just cap off single lamp on diagram.

 

[zappy]

Huh? Looks like you could just use half of it and cap off what you don't use.... hopefully you're only asking for "code purposes"... is it against code? I have no idea, but this isn't exactly a brainteaser, wire-wise...

So I did like you said, and one fixture works fine. I took another new ballast to the next fixture that wasn't working, wired it up the same way, installed two new bulbs, and when I twist the bulbs, the lights comes on for a second and shuts off. Any ideas? i'm gonna take that new ballast down and install another new ballast to see what happens.

 

[zappy]

So I did like you said, and one fixture works fine. I took another new ballast to the next fixture that wasn't working, wired it up the same way, installed two new bulbs, and when I twist the bulbs, the lights comes on for a second and shuts off. Any ideas? i'm gonna take that new ballast down and install another new ballast to see what happens.

I swapped the new ballast, and put in another new ballast, and now it works, so it's a bad ballast from the factory.

 

[zappy]

I swapped the new ballast, and put in another new ballast, and now it works, so it's a bad ballast from the factory.

Actually, I messed up I put the two blues from the ballast together. Oops. lol

 

[Flicker Index]

The ballast will tell you the number of lamps and how to wire them.

Not always. Even if the label does not say so, the detailed specifications quite often allow more load variety.
Generally, operating fewer lamps result in elevated output on the remaining lamps.