How to size an electronic ballast for fluorescent lights?

[.45Cole]

From what I can gather, you just match up the wattage rating and the mfgr recommendations for the number of bulbs.
I was looking at T5 grow lights to get a head start on veg, and roses. I can get a 4 light ballast for ~$30 and bulbs for ~$4. With a timer and wire, that's less than $50. My 8 bulb 4' light was cheap at $100.

Gory details:
T5 @ 54W each
need a F54T5 that can run 4 bulbs and that's it? (I know about the different ballasts, but most are preprogrammed and that's what I'm after, no dimmer)
Wire in parallel.

[Petrol & Powder]

Wow, someone in Colorado that doesn't know how to set up a grow light. [smilie=f:

[crazy mark]

The ballast should have a wiring diagram on it. T-8 tombstones should be ok. Hope you are retrofitting a 4 tube f32t8 fixture. As the f40t12 fixtures are a pain to do. At work we replaced the t-12 fixtures with t-5's. One tidbit the f-x number means x times 1/8 of an inch. T-12's are 1 1/4" and T-8 are 1" so T-5 are 5/8".

[dakotashooter2]

Grow lights and guns ? You just moved yourself up on the BATF watch list..............................

[rush1886]

T5 lamps will NOT work in T8 sockets. T12's and T8's will interchange, but T5's are much smaller OD. Ballasts will always have a description and probably a schematic on them, stating how many of what Tsize and wattage lamps it will run.

Be very aware that 54W, T5 lamps are High Output lamps, and WILL generate a hefty amount of heat, which will need to be diffused somehow. Just be very careful about mounting the fixture in direct contact with anything flammable. Better would be to stand it off the surface by 4"-6".

And I don't live in CO!

Looking back at your "gory details", vs description of the fixture (8lamp), you'll need 2ea 4 lamp ballasts, and wire to necessity.

[.45Cole]

I figured I'd get grow light grief as I typed the post. It just seems to me there would be more to it than buying a T5 54W ballast, and matching the number of tubes. Guess it's that simple. I have the 8 bulb 4' setup already. I think I can build a setup for less than I paid the first time.
As a side note, they are great for starting seeds, keeping roses going, and they do great for my herbs. I have a fan wired into the fixture, when the fixture is on, the fan runs.
Since the law passed, grow lights are super expensive.

[crazy mark]

T5 lamps will NOT work in T8 sockets. T12's and T8's will interchange, but T5's are much smaller OD. Ballasts will always have a description and probably a schematic on them, stating how many of what Tsize and wattage lamps it will run.

Be very aware that 54W, T5 lamps are High Output lamps, and WILL generate a hefty amount of heat, which will need to be diffused somehow. Just be very careful about mounting the fixture in direct contact with anything flammable. Better would be to stand it off the surface by 4"-6".

And I don't live in CO!

Looking back at your "gory details", vs description of the fixture (8lamp), you'll need 2ea 4 lamp ballasts, and wire to necessity.

They will with this adapter. I have used them.For the person who has lots of time and likes his fixtures..

Additional Media
https://www.1000bulbs.com/product_image/view/30173?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_d4d7e90204b1248948bfca3ea3978eb188031bb6_ori ginal_x_600_1327922059.jpg)
https://www.1000bulbs.com/product_image/view/30172?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_a7cf52471dccc49f73f66e407defad71012efb25_ori ginal_x_600_1328073050.jpg)
https://www.1000bulbs.com/product_image/view/30171?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_c27ea0c5250a2fa11a8dd35eca167b852c367250_ori ginal_x_600_1328073011.jpg)
Reto-Fit Lampholder for T8 to T5 Conversion Non-Shunted - Use Programmed Start Ballast ONLY - Leviton 13654-EXS

[rush1886]

They will with this adapter. I have used them.For the person who has lots of time and likes his fixtures..

Additional Media
https://www.1000bulbs.com/product_image/view/30173?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_d4d7e90204b1248948bfca3ea3978eb188031bb6_ori ginal_x_600_1327922059.jpg)
https://www.1000bulbs.com/product_image/view/30172?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_a7cf52471dccc49f73f66e407defad71012efb25_ori ginal_x_600_1328073050.jpg)
https://www.1000bulbs.com/product_image/view/30171?x=30 (https://c808505.ssl.cf2.rackcdn.com/34112_c27ea0c5250a2fa11a8dd35eca167b852c367250_ori ginal_x_600_1328073011.jpg)
Reto-Fit Lampholder for T8 to T5 Conversion

Non-Shunted - Use Programmed Start Ballast ONLY - Leviton 13654-EXS



Those are not adaptors-those are replacement tombstones (lampholders).