flourescent ballast question
 

ok, I've got this EXTREMELY old magnettic ballast that you push and hold the button till the lights turn off...can anyone tell me why a 6500k 48" t8 doesn't fire but a 4100k 48" t8 will? or does it go along the same line as MH bulbs being harder to fire the more kelvin you go up?

As an aside, you can rewire those style ballasts to use a starter. I haven't done it myself but the info should be easy enough to look up, essentially you put a starter inline with the switch, then no more "press and hold".

As far as the lamps go, however, that sounds odd. In general, no, colour temperature shouldn't make a difference, at least I would not have thought so. Technically that's not even true for MH bulbs, it's just that a lot of the MH lamps we use require a pulse start ballast and if you use a probe start ballast then yeah some of them might be a bit finicky.

Anyhow my first guess is check the lamp, maybe it's no good. Do both lamps fire up OK on another ballast? If so, then maybe the ballast is just a little too finicky for the one.

Re: flourescent ballast question
 

wrong type of ballast for the bulb. there are three types, rapid start, instant start and something else which you have.

spend a couple bucks and get a electronic ballast for your tubes. there are about 30.00 for an advance magnatec.

Steve

I agree with stir Crazy I would just go out and buy a new balast!!!

Re: flourescent ballast question
 

Is there going to be a difference between two T8 lamps though? I.e. 4100K vs. 6500K. I thought pretty much all lamps these days use the same starting method.

Although I agree, for the amount of effort it would take, one would be further ahead to just buy a new ballast and be done with this. So that's my advice as well.

it's not a problem that it doesn't fire, I was just wondering what would be different that causes it not to fire..

Re: flourescent ballast question
 

yes T8's have been around a fairly long time and some are instant start and some are rapid start. its a pain because one of the ballasts will start both but the other will only start one of the types.

Steve