I just bought a couple of new 8-foot flourescent fixtures for my garage/workshop and have some questions. I bought them at Home Depot and they are the “high output, cold weather” type.
My question has to do with the bulbs. They are supposed to take the “T-12” type bulbs. However, on the box the fixtures came in, it says that “T12HO bulbs must be suspended.” Why would I have to suspend these fixtures? Can’t I mount them flush with the drywall ceiling like any other fixture?
– Toolfreak
Replies
The high output generate too much heat? Other than that, I couldn't guess-
ToolFreak: The ballasts for HO fixtures put out a lot more heat so they must be suspended although I think a couple of inches will do. It is a significant safety issue and by code manufactures instructions are incorporated ie; they must be followed. On the other hand these are great fixtures for any close work, I have one 4 foot HO over my work bench and it puts out plenty of light. The bulbs are expensive(my F48T12HO were $17ea!) but IMHO worth it.
KDM, retired electrician
The Bill of Rights
December 15 1791
NRA Endowment Member
LEAA Life Member
CRPA Member
Do they have to be suspended by chains? Or can i simply use wooden spacers? Also, can I use non-HO bulbs with these fixtures?- Toolfreak
Just a note without any research to prove it, but my electrician told me that the t-12 fixtures and bulbs are being phased out, in favor of the quick start t-8's. Not sure of the timing, but maybe 3 years on the fixtures, and 7 on the bulbs.Alan
http://www.alanturnerfurnituremaker.com
T.F.: I always, as I remember it, used chains but wooden spacers should be ok. Notice where the ballast is mounted and leave that part of the back of the fixture clear for air flow. The bulbs are very specific which relates to current. 8 foot HO ballasts put out 800ma, the VHO type (very high output) put out 1500ma. This current would pop regular tubes (430ma)in a heartbeat. Also the base pin setup is different. Lighting these days is quite a subject and the right setup can make a world of difference in the shop or elsewhere. KDM
PS: There is talk about phaseing out T12 tubes but there are so many in service tubes and ballasts will probably be available for some time. If you can afford it buy a box of tubes, that will last a while (10-12,000 hrs each).
Kenneth Duke MastersThe Bill of Rights December 15 1791NRA Endowment MemberLEAA Life MemberCRPA Member
Edited 7/27/2005 9:56 am ET by duke-one
As far as the bulbs go, look for the Kelvin rating - want it up near 5000. there is another rating as regards closeness to sunlight and that goes up to 100.
You want one in the 88-92 range for best color rendition.1 - measure the board twice, 2 - cut it once, 3 - measure the space where it is supposed to go 4 - get a new board and go back to step 1
I'm thinking I'm going to return these fixtures and get something that I don't have to suspend (I don't have much ceiling height). I want something 8-feet long and need something that will start right away in my freezing cold garage in the winter. Any recommendations?- Toolfreak
Go with an 8 foot, 4 bulb T8 fixture. Those are a lot more effecient (less heat) and have a better colour. They cost about 50% more than a good HO fixture.
Mikeplease excuse my spelling.
With the idea (probably smart) to return your lights, replace them with T-8 bulb fixtures. The key is they have electronic ballasts, lighter and more effecient than the old magnetic ballasts. They are almost instant start, faster than any magnetic ballast. They work well in the cold. I have them in my garage for two winters now, and they light just a heart beat slower than my incandescent bulb fixture. They started in -9°F mornings just fine!
True, T-8 bulbs are only 4-foot long. Home-Depot sells an 8-ft fixture with 4 bulbs. But the 4-foot shop lights are so cheap that I can't pass them up. You can get T-8 bulbs in all sorts of colors and temperatures for your special purposes.
So T-8 electronic ballast lamps start fast, are more effecient (less waste heat), work in the cold and last longer. You can get electronic ballasts for T-12 bulbs, too. But you have to then replace the old ballast - it's actually pretty easy. But the real reason to get electronic ballasted lamps into your shop is safety!!!
Electronic ballasts are really oscillators putting out about 30 khertz. This means you see no strobe effect on moving blades in your saws looking like they are still! Older magnetic ballasts operate at the normal 60 hertz and you can easily get fooled by strobe effects, if you're not careful.
Try them, you'll like them! One note: because they run at higher frequencies, there are electrical interference issues. Look out for warnings: not for residential use. I have used the low-priced specials from Home Depot and Loews with no problems. My computer room uses these same lights with no problems from either the computer or my FM receiver. My TV right upstairs has no problem, either.
Hope this helps make a decision.
Not a bad idea to return the T12s and get T8s. They are also available in 8 ft and in HO. Also many more choices in color temperature (whiteness or blueness of light, to simplify it). The fancy colors are more or much more expensive. I'm not sure if that will make a difference for wood working other then finishing. Use a "true daylight" in a smaller fixture for color comparisons or use sunlight. Graingers.com has all of this even if just as a reference. The energy savings in T8s is from the closeness of the phosphor (the white powder on the inside of the glass) to the ultraviolet arc in the middle of the tube.
http://www.grainger.com/Grainger/wwg/catalogPDF.shtml
KDM
Kenneth Duke MastersThe Bill of Rights December 15 1791NRA Endowment MemberLEAA Life MemberCRPA Member
Edited 7/27/2005 9:11 pm ET by duke-one
Edited 7/27/2005 9:15 pm ET by duke-one
Definitely return the T12 fixture. Go with T8 electronic ballast as others have accurately opinioned. I have 15 in my shop. Four footers, two bulbs per. No problems. Each has a chain for switching off/on as needed. Why burn all when working in one area? Got them cheap from Home Depot but they do not list them now for what I paid. I ordered on net and waited almost three months before they arrived. Typical for Home Depot. I only shop them when all else fails.
A bad day woodworking is better than a good day working -- yes, I'm retired!
Why turn in the fixture? The size for T12 and T 8 is the same. T12 fits in T8 and T8 fits T12. Hilmar
Not positive but was informed by several "experts" that T8 bulbs must not be used in T12 fixtures and vice versa. Something about the ballasts????
May not be correct but that is what I was told.
A bad day woodworking is better than a good day working -- yes, I'm retired!
Depend, some fixtures are rated for both but most are one or the other. Check the box for info when you buy.1 - measure the board twice, 2 - cut it once, 3 - measure the space where it is supposed to go 4 - get a new board and go back to step 1
This forum post is now archived. Commenting has been disabled