exam question

jcgjupiter · Apr 16, 2004

On a recent 7 question calc test.

A question went something like this:

A commercial/industrial building with 2 tenants with a single service. What is the total demand on the service.

tenant one:
15000 sq ft
and so on listing a full list receptacle count, AC and Heat, pumps, welders etc and the specs.

and then it would show tenant two with another list of stuff. my question is in tenant two it listed a 1500 watt microwave oven and a 12 amp refridgerator. Do those link of item have to be including in calculation the demand for the service. I thought since they plug into regular outlets, they would be covered in the 180 va per outlet calculation. Are you supposed to include anything that's listed.

Thanks for any advice in advance.

jeff43222 · Apr 16, 2004

Re: exam question

Originally posted by jcgjupiter:
On a recent 7 question calc test.

A question went something like this:

A commercial/industrial building with 2 tenants with a single service. What is the total demand on the service.

tenant one:
15000 sq ft
and so on listing a full list receptacle count, AC and Heat, pumps, welders etc and the specs.

and then it would show tenant two with another list of stuff. my question is in tenant two it listed a 1500 watt microwave oven and a 12 amp refridgerator. Do those link of item have to be including in calculation the demand for the service. I thought since they plug into regular outlets, they would be covered in the 180 va per outlet calculation. Are you supposed to include anything that's listed.

Thanks for any advice in advance.

Good question. I suppose they could be considered separately under the "appliances" calculation, but I have a feeling they only included the information in the question to throw people off. Usually the "appliances" calculation includes things like dishwashers, water heaters, and stuff that doesn't tend to get plugged into general-use receptacles.

bphgravity · Apr 16, 2004

Re: exam question

I agree with Jeff. Cord-and-plug connected equipment that is not fastened in place is generally under the general receptacle load calculation. I personally would not add the loads into the calculation.

jcgjupiter · Apr 16, 2004

Re: exam question

Thanks, I thought they might have just tried to throw me off.

luke warmwater · Apr 16, 2004

Re: exam question

I agree with the others, don't count them.
The same as if you have your 2 required small appliance circuts, but give the dining room it's own dedicated circut.
But the 180va per device that you mentioned is not for residential.
it's 3va per sq.ft.

pierre · Apr 17, 2004

Re: exam question

220.3(B)(1)Specific Appliances or Loads.
An outlet for a specific appliance or other load no covered in (2) through (11) shall be computed based on the ampere rating of the appliance or load served.

Yes you would use these for the calculation.

Pierre

charlie b · Apr 17, 2004

Re: exam question

Pierre, I agree with the others. Within the range of 220.3(B)(2) through (B)(11) comes 220.3(B) (10) Dwelling Occupancies.

In one-family, two-family, and multifamily dwellings and in guest rooms of hotels and motels, the outlets specified in (1), (2), and (3) are included in the general lighting load calculations of 220.3(A). No additional load calculations shall be required for such outlets.

(1) All general-use receptacle outlets of 20-ampere rating or less . . . .

It does not matter that a homeowner plans to plug a microwave into a specific outlet and leave it there forever. That outlet is a ?general-use receptacle outlet,? and is counted within the 3va per square foot. The homeowner might choose to move the microwave, and plug a toaster into that outlet instead.

The refrigerator is a bit more open to interpretation. I say that the same concept applies, that its outlet is a ?general-use receptacle outlet.? I recognize that the fridge is often placed into an area designed to accommodate its size and shape, and that there is likely to be no other place in the kitchen that the fridge would fit. But that fact does not change my interpretation. The fridge, like the microwave, is not immovably fastened in place.

Of course it is acceptable to include a line item for each of these two appliances in a service calculation. The NEC provides minimum requirements, and you can build a larger service if you like (and if the homeowner will pay for it). But this is an exam question. It must be answered in accordance with the specific NEC minimum requirements, or it will be marked as a wrong answer.

pierre · Apr 17, 2004

Re: exam question

220.3(B)(10)
The way I am reading this follows (1), (2), and (3). These do not apply to (B)(1). IMO

Specific appliances do not fall under bathrooms, lighting, and garages/outdoor receptacles.

read this a little more carefully and see what you think - than lets think outloud together.

Pierre

bphgravity · Apr 18, 2004

Re: exam question

Originally posted by jcgjupiter:
A commercial/industrial building with 2 tenants with a single service. What is the total demand on the service.

What does this question have to do with Dwellings?

charlie b · Apr 18, 2004

Re: exam question

Originally posted by pierre: 220.3(B)(10)The way I am reading this follows (1), (2), and (3). These do not apply to (B)(1). IMO

I am not certain that I understand what you are saying here. But reading the section again, I noticed for the first time that the code writers have violated the rules of paragraph structure and numbering. Let me explain the violation, and tell me if this is the cause of our difference in interpretation.

The paragraph identification scheme for NEC articles starts with a number, then a period, then another number. Lower level paragraphs have a capital letter within parentheses, then a number within parenthesis, then a small case letter within parentheses, and finally a roman numeral within parenthesis. An example would be ?123.45(A)(7)(b)(iv).?

But the subparagraphs under 220.3(B)(10) are not identified with small case letters within parentheses. Instead, you have another number within parenthesis. So we have a subparagraph numbered, ?220.3(B)(10)(1).? This violates the rules of paragraph structure.

So let me offer the following guess. When you read 220.3(B)(10), and see that it talks about ?(1), (2), and (3),? you infer that it is talking about the items above, namely 220.3(B)(1), and 220.3(B)(2), and 220.3(B)(3). What I infer is that 220.3(B)(10) is talking about 220.3(B)(10)(1), and 220.3(B)(10)(2), and 220.3(B)(10)(3). Here is what I think that is telling us:

All general use receptacle outlets are included in the general lighting load calculations, and

The outdoor, basement, and garage outlets of 210.52(E) and (G) are included in the general lighting load calculations, and

The lighting outlets of 210.70(A) and (B) are included in the general lighting load calculations .

shaun · Apr 21, 2004

Re: exam question

Previous statement posted by:jcgjupiter

"A commercial/industrial building"; "my question is in tenant two it listed a 1500 watt microwave oven and a 12 amp refridgerator. Do those link of item have to be including in calculation the demand for the service."

In what I gather jupiter, is that first of all your given is that it is not residential so we can pretty much throw that out of the window, The one thing mike holt has taught me is "Know your Question". I would have to agree with Pierre and Gravity on this one my friend and as far as the paragraph structure is concerned in my opinion it seems that they followed the normal ARRANGEMENT

I just had to do that, because all over this forum I have been seeing that word mispelled (ARRAINGEMENT) No pun intended, he he!

drg · Apr 21, 2004

Re: exam question

There is no "d" in refrigerator either MR. spelling bee , everyone makes spelling errors so don't have to much fun out of it...we all have our turn with this one.

John

shaun · Apr 22, 2004

Re: exam question

Previous message posted by: DRG
"There is no "d" in refrigerator either MR. spelling bee , everyone makes spelling errors so don't have to much fun out of it...we all have our turn with this one."

John you can see, it is very easy to "cut and paste", just as I did your post and notice how the quotations are inserted meaning that was his exact words, also I did not mean for anyone to get offended by what I said, IMO, this forum is for sharing ideas and learning, not for name calling, however if you are the one guilty for that mispelling, then I apologize, but now you know how to spell it correctly and the purpose of this forum has been fulfilled! So, I have done my job, and by the way if there is some error in anything that I may do, please correct me. Constructive criticism is how measure what we know. To the forum I truly apologize, but for the name calling, that sir was inappropriate!

shaun · Apr 22, 2004

Re: exam question

"Constructive criticism is how we measure"

Now see there is an error on me, I forgot to put we after how in my post.

Sincerely,

Shaun

iwire · Apr 22, 2004

Re: exam question

Is yous guys gonna be ok?

shaun · Apr 22, 2004

Re: exam question

hey IWIRE,

Didn't know that you were logged on! Yes I will be fine and I will say it again If I offended anyone I am sorry!

iwire · Apr 22, 2004

Re: exam question

Originally posted by shaun:
hey IWIRE,

Didn't know that you were logged on!

I am omnipresent.

shaun · Apr 22, 2004

Re: exam question

truly magnificent

drg · Apr 22, 2004

Re: exam question

Shaun

I was kind of half joking when I made this comment and did not mean to intimidate you and ruin your day either.

John

roger · Apr 22, 2004

Re: exam question

omnipresent

I'll have to remember that one.

Roger

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