[yasciti]

Hi

I was told that electronic ballasts can be wired to power multiple tubes of lesser wattage aslong as their wattage = or is < the ballasts power output rating.

I have a 2x 58w ballast & want to know how to wire it in order to power 2x 30w 2x 18w tubes. I have it wired to power the 2 30w which works fine. How do I add the other 2?:confused1:
Attached is a pic of the ballasts wiring diagram.
Any help would be much appreciated.
Thanks.

 

[HolyAngel]

Connect the end of each 30w tube to an 18w tube and connect that end to the ballast like it should be, so they're in a series

 

[sod4]

Connect the end of each 30w tube to an 18w tube and connect that end to the ballast like it should be, so they're in a series

Should they not be parallel? You'd want the same voltage drop across both tubes with a different amount of current.

 

[Wasserpest]

While you can wire smaller bulbs in series to trick the ballast thinking it is one bigger bulbs, I would only attempt that with same wattage/size/type bulbs.

I'd say get another ballast if you want to power more than two bulbs (which the ballast is spec'd for).

 

[yasciti]

Thanks for the replys.

Holyangel, just to clarify...
Do you mean that I should connect the ends 18w to the 30w, & then connect the 18w back to the ballast? Could this run just 1 extra 18w then? I take it the 18w tubes don't need to be bridged as well, right?
Thanks.

 

[HolyAngel]

well since the ballast only drives 58 watts total per channel, and a standard bulb can be safely ODNO'D with up to 4x the normal power, there should be no way for anything to happen to either the bulbs or the ballast.

As for the clarification, you'd connect the power leads to one of the 30w like normal, then connect the other side of that one 30 to an 18, and then connect the end of the 18 to the yellow/ground circuit like normal, like it was originally before adding the 18. It'll either work or it wont.
The other option is connect two 18's together for one channel of the ballast, and the two 30's together for the other channel, basically the 18's would be over driven a little, and the 30's slightly under driven.

 

[yasciti]

Thanks Holyangel, it worked.
Is there any limit to how long the cords can be? I mean the cords from ballast to tube.
Thanks again.

 

[HolyAngel]

Great! And I Believe the recommended limit is 3 feet for the wires from the ballast to bulb.