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commercial receptacle limits

Merry Christmas
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roger

roger

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Location
Fl
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Retired Electrician
Re: commercial receptacle limits

Ron in the question 115 v is specified.

"How many receptacles can be installed on a 20 amp 115 v circuit in a commercial office building?"

Now,
220.2 Computations.

(A) Voltages. Unless other voltages are specified, for purposes of computing branch-circuit and feeder loads, nominal system voltages of 120, 120/240, 208Y/120, 240, 347, 480Y/277, 480, 600Y/347, and 600 volts shall be used.
Click to expand...
Roger

[ July 30, 2003, 02:41 PM: Message edited by: roger ]
 
B

bennie

Esteemed Member
Re: commercial receptacle limits

Lets examine this from another direction.

With 115 volts, 180 VA = 1.56 amps per device.

1.56 amps X 13 =20.28 amps. Drop the .28, as permitted by 220.2(B)


With 120 volts, 180 VA=1.5 amps per device.

1.5 amps X 13= 19.5 amps.

So I conclude 13 is correct with both voltages.
Anyone agree.
 
charlie b

charlie b

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Location
Lockport, IL
Occupation
Semi-Retired Electrical Engineer
Re: commercial receptacle limits

Bennie: Perhaps you missed your calling. You should have been an Accountant (Motto: ?What number did you have in mind??).
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: commercial receptacle limits

Ok, it's unanimous, there is a limit on the number of receptacles on a commercial circuit. (220.3(B)(11) Other Outlets) :)

Roger
 
B

bennie

Esteemed Member
Re: commercial receptacle limits

Roger: Do you or anybody else know what the answer is on this particular test?
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: commercial receptacle limits

Bennie, the answer is 12.

Ron,
I mentally skipped the 115v reference in the question.
Click to expand...
it,s strange how our brains can refuse to see things at times.

For fun see the following, and follow the instructions.


How Many Do You Count?


This takes about 30 seconds.





Ok!! How many do YOU see???






Count the "F's" in the following text:
FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS






Managed it? Scroll down only after you have
counted them, okay?







How many? 3?
Wrong, there are 6 !!--no joke.
Read it again.
The reasoning behind is further down.


The brain cannot process "OF".
Incredible or what?
Anyone who counts all 6 "F's" on the first go is a genius. Three is normal, four is quite rare.

I got four when I first read it, this reinforces what we all know, I'm rare :D


Roger

[ July 30, 2003, 04:17 PM: Message edited by: roger ]
 
R

ronaldrc

Senior Member
Location
Tennessee
Re: commercial receptacle limits

Roger where did you get that magic number of 13?

My 2002 NEC handbook has an exhibit 220.4 which shows 10 for a 15 amp. circuit and 13 for a 20 amp. circuit.


Check out page # 103 exhibit 220.4

By the way Roger check out exhibit 220.3 you'll get a kick out of the 360 va recpt. it shows there.

Click to see photo from 2002 NEC Hand book


Ronald :)

[ August 09, 2003, 07:49 PM: Message edited by: ronaldrc ]
 
roger

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Re: commercial receptacle limits

Hello Ronald,
Roger where did you get that magic number of 13?
Click to expand...
You can bet if I ever have to bring this question up again it won't be in there.
laughing-smiley-004.gif


Roger
 
B

bennie

Esteemed Member
Re: commercial receptacle limits

Back to the subject...What test is this question on? Who administers this exam. I will write them and show the math. This should be retracted if the correct answer is shown as 12.

Should I fail the test by answering with 13, I would file a legal appeal, I would win.

When a testing organization writes a test, the test should be accurate according to accepted technology, compliance with the NEC is then assured.
I am fully aware that tests are one method for determining a persons qualifications, an incorrect exam endorsed by influential professional "code experts" is a step backwards.
 
joe tedesco

joe tedesco

Senior Member
Location
Boston, Massachusetts
Re: commercial receptacle limits

bennie:

You would be wasting your very precious time and money, the correct answer is 12 and it is based upon the rule cited in more than one reply here!!

[ August 01, 2003, 05:30 PM: Message edited by: joe tedesco ]
 
R

ronaldrc

Senior Member
Location
Tennessee
Re: commercial receptacle limits

Joe please read 605.8 (C)of the 2002NEC. this is the closest thing I've found to back Bennies thirteen number this is recpts. in office partitioned walls.

Then refere back again on my post on the example for maximum amount of recpts on a 20 amp. circuit this thread 2nd page.

Ronald ;)
 
joe tedesco

joe tedesco

Senior Member
Location
Boston, Massachusetts
Re: commercial receptacle limits

Section 605.8(C) cannot be applied to the question that Roger posted. Please read the Scope of the article.

The question is clear and it was designed to take into consideration the rule in 220.2(A)

"Unless other voltages are specified ...."

The question specifies 115 volts so that voltage must be used in the calculation order to get the correct answer.

:)
 
R

ronaldrc

Senior Member
Location
Tennessee
Re: commercial receptacle limits

Joe thats a good point but I believe the 115 volts was a mistake the nominal voltages should be used in the real world. 115 isn't a nominal voltage if this is the case 12 or 13 should be accepted.


Also Joe this answer goes against the NEC specs.
It plainly states that 13 recpts. can be installed on a 20 amp. circuit.

Ronald :)

[ July 31, 2003, 06:28 PM: Message edited by: ronaldrc ]
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: commercial receptacle limits

Joe,
Who is permitted to "specify the voltage"? What would prevent an installer from "specifying" 126 volts and installing 14 duplex receptacles on a 20 amp circuit?
Don
 
R

ronaldrc

Senior Member
Location
Tennessee
Re: commercial receptacle limits

Roger you said this had something to do with the handbook and I posted it thats the end of my part in this arguement.

You know what really gets to me.When the NEC discusses AFCI and GFCIs they use the voltage of 125 volts which is not a nominal voltage.I like to discuss electrical theory and the like but thing like that is what have burned me out in this trade.

Ronald :confused:
 
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