High Bay Flour. Lighting

Status
Not open for further replies.
F

farmaped

Member
Location
PA - USA
Occupation
Engineer
Good Morning,
A few questions on High Bay Flourescent lighting, typically found in commercial, industrial, and wharehouse environments. 25 to 35 feet height mount.
1. T5 or T8 Electronic ballasts, is one superior to the other at this height?

2. Is Harmonic Distortion a problem? Are their guidelines concerning the lighting load vs. capacity of the service that can estimate the THD?

3. If you had a 480V 3P 3W service, what supply voltage would you utilize? 480V 1P, 277V 1P, or 120V 1P.
I understand the wiring advantage with the 480V 1P, however does this limit the fixtures available and the increased price of ancillary equipment (switches, contactors, breakers, etc.).
277V would require an isolation transformer, which may not be a bad idea if THD is an issue. And, from the little I've seen, most ballasts are 120-277V.

4. Is there a light fixture height mounting restriction in the NEC, based on the supply voltage?

Alot of questions, any advice is truly appreciated.
 
farmaped said:
Good Morning,
A few questions on High Bay Flourescent lighting, typically found in commercial, industrial, and wharehouse environments. 25 to 35 feet height mount.
1. T5 or T8 Electronic ballasts, is one superior to the other at this height?

2. Is Harmonic Distortion a problem? Are their guidelines concerning the lighting load vs. capacity of the service that can estimate the THD?

3. If you had a 480V 3P 3W service, what supply voltage would you utilize? 480V 1P, 277V 1P, or 120V 1P.
I understand the wiring advantage with the 480V 1P, however does this limit the fixtures available and the increased price of ancillary equipment (switches, contactors, breakers, etc.).
277V would require an isolation transformer, which may not be a bad idea if THD is an issue. And, from the little I've seen, most ballasts are 120-277V.

4. Is there a light fixture height mounting restriction in the NEC, based on the supply voltage?

Alot of questions, any advice is truly appreciated.
Click to expand...

1. T5 = more efficient
2. Never heard of that being a concern, but that is just me. I never worried about it when I was designing stuff.
3. 277 if you have it. Won't have any trouble finding equipment and will still benefit from the higher voltage.
4. No.
 
1. The answer depends on the condition. The best lumen output of T5 is around 95 degree temperature. The best lumen output of T8 is around 77 degree temperature. T5 normally has higher lemen output per lamp. So if the warehouse has high ceiling (>35 feet) and is dry storage, T5 may be the good choice. If the warehouse has low ceiling (<35 feet) and is dry storage, T8 may be the good choice. If the warehouse is a cold storage, you maybe use T8 depend on the cold temperature, but definitely not T5. If it is a freezer, you may have to use metal halide.

2. Not realy.

3. Most T5 and T8 are rated 277v for warehouse. I believe 480V single phase T5 and T8 electronic ballast shall be available. You need check with local rep.

4. No mounting height restrict from NEC. But you need to do photometrics calcualtion to make sure the lighting level meets your client's requirement.

Hope it help.

David
 
Thank you for the replies.
I have talked with other lighting reps and they don't seem to recall a customer have distortion issues with the electronic ballasts as well.
Yes 210.6 C&D was what I was thinking, I just couldn't remember the article #. It discuss minimum height (versus maximum), so I am clear on this.
 
Status
Not open for further replies.
Top