Store Lighting Continuous Load?

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infinity

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New Jersey
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I don't believe that it does tell you that. The questions assumes that all of the lighting will be on for 3 hours or more but that also means every single light in the store must be on for 3 or more hours.
 

Dennis Alwon

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Chapel Hill, NC
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Where does it say that the 3VA/sq.ft does not account for the continuosity of that load?
Where does it say it does. To me that is the more important fact. If I tell you 3va/sq.ft, imo then continuous load must be considered on top of that. How would you do residential- are we to assume there is no continuous in that and yet there is continuous load in the other?
 

jumper

Senior Member
Where does it say that the 3VA/sq.ft does not account for the continuosity of that load?

The what?:happyno: Nice try.

Anyways, I have been around and around this example with charlie b twice. We disagree.

The example says to do it this way, and every test and exam prep question I have seen does it this way.

Right ,wrong, or indifferent: I do it this way.
 

Hv&Lv

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-
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Engineer/Technician
I have been taught that store lighting is to be assumed continuous loads. A quick walk around any store in a mall, or for that matter, most mom and pop stores turn their lights on in the AM and off at closing. thus, more than three hours...;)
 

hmspe

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Temple, TX
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PE
With current energy codes I would tend to not apply a 125% multiplier to the 3VA/s.f. The allowed watts/s.f. in the IECC is far less than 3 so I believe the NEC table values have more than adequate margin without adding an extra 25%..
 

George Stolz

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Windsor, CO NEC: 2017
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I would say the definition of continuous load in Article 100 tells us that.

The problem I have with the assumption is that it ignores the fabric of the term. If I install a bunch of skylights, install daylighting controls, and set business hours for 8am - 5pm then I still have a continuous load? I detest assumptions, especially if they're not backed up by a reference. :rant:

Where does it say that the 3VA/sq.ft does not account for the continuosity of that load?
Where does it say it does. To me that is the more important fact. If I tell you 3va/sq.ft, imo then continuous load must be considered on top of that. How would you do residential- are we to assume there is no continuous in that and yet there is continuous load in the other?

You're getting to the core of the problem as I see it. There are only four instances in the entire NEC that there is a specific situation called out as a continuous load for feeders and/or services: 426.4, 427.4, 625.14, 625.21. IMO, it is then up to the designer to determine what will stay on for three hours and what won't.

If they write a test question (as is shown in the OP) and elect to call it out as a continuous load in the question, okay then, it's fair. Expecting two different people to feel the same way with no directive one way or the other is hogwash, IMO.

Where does it say that the 3VA/sq.ft does not account for the continuosity of that load?
The what?:happyno: Nice try.

What, I can't be funny? :happyyes:

Anyways, I have been around and around this example with charlie b twice. We disagree.

The example says to do it this way, and every test and exam prep question I have seen does it this way.

Right ,wrong, or indifferent: I do it this way.

I have been taught that store lighting is to be assumed continuous loads. A quick walk around any store in a mall, or for that matter, most mom and pop stores turn their lights on in the AM and off at closing. thus, more than three hours...;)

So, word of mouth and a handshake replace clear code requirements?

The problem I have is: I don't believe in it, and don't want to teach it that way (it feels like passing along inaccurate information), but hate to teach contrary to the test and start leading people to wrong test answers, if everything is set up to the opposite of my opinion. You know what I mean?
 

jumper

Senior Member
Yes, I know exactly what you mean. If you wish to explain the discrepancy(?), great: i.e. is every light on for 3 hours for the feeder/service calculation?

However, if this is a test prep course you are teaching-the example rules the day.
 
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