# Ballast Wiring Question for the Experts / Experienced



## AaronT (Apr 26, 2004)

If I were to buy one ballast that could run 4 HO 54 watt T5 HO bulbs is there a way to wire such that I can use 1,2,3 or 4 bulbs at a time? Those of you who have the Tek fixture will know what I'm asking. On those fixtures if you don't have both bulbs in a pairing installed neither one will light up.

I'm asking because I'd like to build a light that allows me to change the light levels depending on what's on the shelf of my rack at the time.


----------



## dennis (Mar 1, 2004)

It will depend on the ballast you use. The Advance Centiums, and I assume whatever Tek uses, are capable of running any combination of bulbs up to their max wattage. However, the wiring patten is different for 1, 2, etc. 2 bulbs are supposed to be wired in series so you would need both for 1 to work.

The solution then is to use a different ballast, one capable of powering 54 watts for each lead. The Workhorse ballasts should do that. I don't know which model you need but their website is very good. Ignore the fact that you are using T5 and searc for a ballast that will power 4x55/65 PCs in parallel.


----------



## AaronT (Apr 26, 2004)

Sweet, that's what I thought. I always get parallel and series mixed up so I wasn't sure which way was which.


----------



## dennis (Mar 1, 2004)

Series: power-bulb-bulb-neutral/ground
Parallel: power-bulb-neutral-bulb-power

Parallel _usually_ has 2 bulbs sharing a common neutral but each bulb has its own power. A ballast that will power 4 bulbs will generally have 6 wires, 2 red, 2 blue and 2 yellow. They are wired with 2 sets of 2 bulbs in parallel. The red and blue wires are power wires (hot) each set going to one set of parallel bulbs with one wire for each bulb. one yellow wire is the neutral for each set o bulbs and is pig-tailed off or wired in such a way as to complete the circuit for both bulbs.


----------



## AaronT (Apr 26, 2004)

Thanks again Dennis. The Workhorse ballasts are the ones I was looking at the it looks as though they're setup in this exact way, only with 4 red wires and 2 yellow wires. This is for a project down the road. I'm in the planning stages for now until I can raise the funds.


----------



## epicfish (Sep 11, 2006)

Aaron,

If you're every looking for wiring diagrams for the WH ballasts, Fulham - Fulham Online has a "configurator" where you input the number and type of bulbs you want, and it'll spit out the ballast model and wiring diagrams for you. =)

That's what I used when I was contemplating a DIY T5 setup.


----------

