Lighting amp draw


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Old 05-19-16, 11:32 PM
J
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Lighting amp draw

I have another post in the AC/DC forum but this question is better suited here I believe. the shop is 45x50x14 and looking to get lights up in it. I am concerned about amp draw due to some long runs in the barn... 140 feet or so. With these kind of runs 2 amps per light and only 5-6 lights gets me up in the 10 ga wire arena. I did the simple math on the lights I am looking at and with the straight up watts per bulb / 120 volts came up with 2 amps. Talked with an electrical engineer and he said really what you want to know is what does the ballast draw cause that is you total draw per light. Can not find the specs on the ballast anyone know if 2 amps is about right.... Also thinking of going 240 on them to reduce the amp consumption thus reducing wire size Was planning on 3x rows of 4 in the shop with room for 4x more if needed.

Here are the lights I was looking at /// Metalux HBL-Series High Bay Shop Light (Common: 4-ft; Actual: 19.6-in x 49.4-in) Item #: 599275 | Model #: BL-Series High Bay Shop Light (Common: 4-ft; Actual: 19.6-in x 49.4-in)

Commercial grade high bay
High-bay offers 18,900 lumen package is 51% more efficient than similar 400-watt metal halide
Included 5-year warranty, cULus listed for high ambient environments up to 55C (131F) suitable for damp locations
Twist-lock lamp holders and a factory installed disconnect for make installation safe and convenient
Die-formed segmented reflectors provide exceptional color rendering, uniform brightness and light distribution control ////


thoughts
 
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Old 05-19-16, 11:48 PM
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Well just found some information... looks like 240 is out as the ballast type seems to be 120/277. Am I correct. Still did not find out the amp draw but looks like 2 Amps might be a little high. Below is what I found along with a bunch of other stuff that I do not understand. Found it under the downloads under specs for the type of light listed below.

The HBL comes with a standard Class "P" electronic ballast and twist-lock lampholders. UL/cUL listed for high ambient environments up to 55C (131F) for all lamp and ballast combinations listed. Suitable for damp locations.
 
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Old 05-20-16, 12:03 AM
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Usually with a 120/277 ballast that just means the minimum and maximum voltage so they should work at 240 or 208. Wait for the pros to weigh in on this thread or call the manufacturer.
 
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Old 05-20-16, 11:46 AM
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With these kind of runs 2 amps per light and only 5-6 lights gets me up in the 10 ga wire arena.
The NEC voltage drop of 3% is only a recommendation, not a requirement, but it makes sense to size your conductors accordingly since it is a new install. I'm sure you already realized that.
 
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Old 05-21-16, 07:42 AM
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Ray is correct. So any voltage within those specs will work.

As they are electronic ballasts.... voltage drop is not important as long as you don't go below 120v. .
 
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Old 05-21-16, 10:06 AM
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Ok thanks... going to wire these 240 per an electrical engineers suggestion to help with Volt drop. I knew that volt drop affected motor operation and life but also thought it increased the chance of fire.... motors I can replace .... barns I do not want to replace. HA
 
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Old 05-21-16, 11:00 AM
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I suggest just using #12 wire on a 20 amp breaker(s). Voltage drop will not be an issue even at 150'
 
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Old 05-21-16, 11:04 AM
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Based on the specs for that fixture... it's 196 watts maximum.

That means at 120v it's 1.65 amps per fixture and at around 240v would be .82A.
So you could figure 1A per fixture in your calculations.
 
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Old 05-31-16, 12:16 AM
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Thanks PJmax--- did you find the specs somewhere or did I just overlook the way to figure them on the specs I gave. sorry for the late reply on this-- been out working trying to get the barn ready for lights all weekend-- burning the midnight oil or midnight sun here in Alaska.

Based on those calculations with a sub panel install I should be fine with 12 gauge wire if I run them 240 volt. Never done that for lights so may be back here for some help on that one when the time comes, cause I assume they are set up to run 120 plug and play.
 
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Old 06-14-16, 04:53 PM
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Sorry for waiting so long to get some images for review on the ballast I am going to use but finally was able to get them.

According to the pics looks like the total amp draw will be 1.87 amps based on the numbers from both ballast wired at 120V

Correct
 
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