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OK, I haven't studied this issue, but it seems like there's a prima facie argument in favor of the 13 receptacle limit. Namely:

1) 210.11 "Branch circuits for lighting and for appliances . . . shall be provided to supply the loads calculated in accordance with 220.10."
2) 220.10 "Branch-circuit loads shall be calculated as shown in 220.12, 220.14, and 220.16."
3) 220.14(I) The 180VA rule
4) 210.19(A)(1) "Branch-circuit conductors shall have an ampacity not less than the maximum load to be served."

So it seems like 210.11 is telling us that for compliance with 210.19(A)(1) the article 220 calculation has to be used. If you disagree, what's wrong with this argument?

The situation in article 215 is much clearer, as 215.2(A)(1) states "Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220."

Cheers, Wayne
 
wwhitney said:
OK, I haven't studied this issue, but it seems like there's a prima facie argument in favor of the 13 receptacle limit. Namely:

1) 210.11 "Branch circuits for lighting and for appliances . . . shall be provided to supply the loads calculated in accordance with 220.10."
2) 220.10 "Branch-circuit loads shall be calculated as shown in 220.12, 220.14, and 220.16."
3) 220.14(I) The 180VA rule
4) 210.19(A)(1) "Branch-circuit conductors shall have an ampacity not less than the maximum load to be served."

So it seems like 210.11 is telling us that for compliance with 210.19(A)(1) the article 220 calculation has to be used. If you disagree, what's wrong with this argument?

The situation in article 215 is much clearer, as 215.2(A)(1) states "Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220."

Cheers, Wayne
Click to expand...

Go with the scenario we have going.

30 rec, 5400va, 3 circ.

split the 30 recs however you want among the three circuits.

now add 10 more. you recalc for added recs and add circuits if needed.

we are not saying that you just add recs without adding load.

nothing says split them into 13 recs per circuit

you calc the load per 220 for how many recs, determine how many circuits are needed, install the number of recs among the circuits. how many recs per circuit is not defined.
 
LarryFine said:
Yes, as far as sizing the service for the premises, that is the minimum .


[/FONT]Agreed. 220.14(I) certainly does not specify a quantity of receptacles.


Yes, as far as the allowance for the service sizing is concerned. So far, no power is being consumed.


Yes, because this has nothing to do with the service calculation. Receptacles are not loads.

What do you do if you installed those 13 receptacles on one circuit, and then plug in 13 16-amp loads?


(That's "cite") As has been pointed out many times, the NEC generally prohibits, rather than allows.

You're saying that the minimum allowance for load calculations are also binding on actual installation.

I'm saying that actual usage is what matters for installation. Some circuits get only one receptacle.

220.14(I) doesn't restrict us to 1 receptacle for a large load, nor 13 receptacles for minimal loads.
Click to expand...

:roll::roll::roll::roll: You really believe that huh?


This guy must have it wrong too.

To calculate receptacles in accordance with 220.14(I), multiply the number of receptacles by 180 volt-amperes. For example, what is the calculated load for 30 15-ampere duplex receptacles in a retail store? Multiply the number of receptacles by 180 (30 × 180 = 5,400). The minimum calculated load for 30 15-ampere duplex receptacles in a retail store is 5,400 volt-amperes. The calculated load for 20-ampere receptacle outlets is no different than the calculated load for 15-ampere receptacle outlets. For example, what is the calculated load for 30 20-ampere duplex receptacles in a retail store? Although 20-ampere receptacles have a higher rating than 15-ampere receptacles, the calculated load is exactly the same. The minimum calculated load for 30 20-ampere duplex receptacles in a retail store is 5,400 volt-amperes (30 × 180 = 5,400) (see Figure 3).



The calculated load is used to determine the maximum number of receptacles permitted on a branch circuit in all but dwelling occupancies. The ampere rating of the overcurrent protective device is what determines the maximum number of receptacles on a branch circuit. For example, the maximum number of receptacles on a 15-ampere breaker (or fuse), supplied by a nominal source voltage of 120, is 10.


The calculation can be performed either by converting the ampacity rating to volt-amperes or by converting volt-amperes to amperes. Use Ohm’s Law to find amperes when volt-amperes and voltage are known (I = W ÷ E). Divide 180 by 120. The calculated load for one receptacle supplied by 120 volts is 1.5 amperes (180 ÷ 120 = 1.5).


To find the maximum number of receptacles permitted on a 15-ampere breaker, divide the rating of the breaker by 1.5 amperes (15 ÷ 1.5 = 10). The maximum number of receptacles permitted on a 15-ampere, 120-volt breaker is 10 (see Figure 4). Because of provisions in Table 210.21(B)(3) and Table 210.24, 20-ampere receptacles are not permitted on a branch circuit having a rating of 15-amperes.



Because of the higher rating on a 20-ampere breaker, more receptacles are permitted than on 15-ampere overcurrent devices. The calculated load per receptacle is the same, 1.5 amperes. To find the maximum number of receptacles permitted on a 20-ampere breaker, divide the rating of the breaker by 1.5 amperes (20 ÷ 1.5 = 13.3 = 13). The maximum number of receptacles permitted on a 20-ampere, 120-volt breaker is 13 (see Figure 5). In accordance with Tables 210.21(B)(3) and 210.24, these receptacles can be 15-ampere, 20-ampere or any combination thereof.



Although a single receptacle and duplex receptacle do not share the exact same definition, they are counted the same in a load calculation. Unless specifically stated in 220.14(J) and (K), receptacle outlets shall be calculated at not less than 180 volt-amperes for each single or for each multiple receptacle on one yoke [220.14(I)]. For example, what is the branch-circuit load calculation for 30 15-ampere single receptacles in a retail store? The calculated load for 30 15-ampere single receptacles is the same as it would be for 30 15-ampere duplex receptacles, 5,400 volt-amperes (30 × 180 = 5,400) (see Figure 6).
Click to expand...

https://www.ecmag.com/section/miscellaneous/branch-circuit-feeder-and-service-calculations-part-vii

Add him to the list along with Mike Holt. And everyone that paid Mike Holt to attend one of his code classes/seminars. According to you they were all mislead.

Add to the list the instructors at the DMJATC and all the apprentices that were mislead by the instructors over many, many, many years. Instructors have come and gone over the years and yet the newer instructors teach NEC 220.14(I) the same way.

Add to the list all the IBEW Local union JWs that took code classes, (for their required continuing education for renewing their State Electrical License), at the DMJATC that were told 220.14(I) is used to calculate the total receptacle load determining the maximum number of receptacles that can be connected to a general-purpose branch circuit in a commercial occupancy. Include me in that list.

Add to the list the instructors at the DMJATC that were mislead by instructors for Code classes they are required to attend to meet their employment contract, for their NEC continuing education.

I found an Email for contacting Mike Holt. I am going to send him an email tomorrow with a Link to this thread and ask him for a ruling on 220.14(I) for use determining the maximum number of receptacles that can be installed on a general-purpose 120V 20 amp branch circuit in a commercial occupancy. I hope he responds back. I already know what he is going to say though. 13!
120V X 20 amps = 2400VA / 180VA = 13.

If I can get up early enough in the morning, before 7:eek:oAM ET, I am going to call, I believe the guy I want to talk to, Rick Paul, Electrical Inspections, Richmond VA (1 (804) 646-6959) and ask him how many duplex receptacles I can install on a general-purpose 20 amp branch circuit in a commercial occupancy. I'll be very surprised if he says as many as you want.

I'll even call the electrical inspection department in Des Moines and ask them as well.

Best regards,
Jim
 
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wwhitney said:
OK, I haven't studied this issue, but it seems like there's a prima facie argument in favor of the 13 receptacle limit. Namely:

1) 210.11 "Branch circuits for lighting and for appliances . . . shall be provided to supply the loads calculated in accordance with 220.10."
2) 220.10 "Branch-circuit loads shall be calculated as shown in 220.12, 220.14, and 220.16."
3) 220.14(I) The 180VA rule
4) 210.19(A)(1) "Branch-circuit conductors shall have an ampacity not less than the maximum load to be served."

So it seems like 210.11 is telling us that for compliance with 210.19(A)(1) the article 220 calculation has to be used. If you disagree, what's wrong with this argument?

The situation in article 215 is much clearer, as 215.2(A)(1) states "Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220."



Cheers, Wayne
Click to expand...


Add, Table 210.21(B)(3) to your list.
 
jumper said:
Go with the scenario we have going.

30 rec, 5400va, 3 circ.

split the 30 recs however you want among the three circuits.

now add 10 more. you recalc for added recs and add circuits if needed.

we are not saying that you just add recs without adding load.

nothing says split them into 13 recs per circuit

you calc the load per 220 for how many recs, determine how many circuits are needed, install the number of recs among the circuits. how many recs per circuit is not defined.
Click to expand...

nothing says split them into 13 recs per circuit
Click to expand...

No, of course not. 13 is the max, not a required number. You can install any number of receptacles on the 20 amp circuit as you want. You just cannot exceed 13.

Most electrical drawings that are drawn by an EE will circuit 8 to 10 duplex receptacles for general-purpose in a commercial occupancy.
Why? Just a guess they figure 80% of 2400VA. = 10. Not because he/she is required to by NEC though.



Jim
 
Jamesco said:
No, of course not. 13 is the max, not a required number. You can install any number of receptacles on the 20 amp circuit as you want. You just cannot exceed 13.

Most electrical drawings that are drawn by an EE will circuit 8 to 10 duplex receptacles for general-purpose in a commercial occupancy.
Why? Just a guess they figure 80% of 2400VA. = 10. Not because he/she is required to by NEC though.



Jim
Click to expand...

Nothing says a max of 13 either.

2 circuits for 15 recs, i can put 14 on one and 1 on the other.

my two circuits provide the power for the required load calculation.
 
wwhitney said:
The situation in article 215 is much clearer, as 215.2(A)(1) states "Feeder conductors shall have an ampacity not less than required to supply the load as calculated in Parts III, IV, and V of Article 220."
Click to expand...
I guess this is the main counterargument, that the language in 210.11 contrasts with the clear language in 215.2. The 210.11 language only ever discusses branch circuits in aggregate, never individually, so the requirement to supply the load calculated in 220 applies only in aggregate to the branch circuits, not to each individual branch circuit.

Cheers, Wayne
 
jumper said:
James,

If the calculated load per 220 is 180VA per receptacle, then is the receptacle limited to 180VA installed?

That means no using any receptacle for a load over 1.5A. Think about it. Does that sense?
Click to expand...

NO. That is a minimum for figuring the calculated load (220.14(I)

Go to table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle.

Circuit Rating, amps........ Receptacle Rating, amps.......... Maximum Load,
15 or 20 ...................................15 ................................ 12 amps
20 ...........................................20 ................................. 16 amps
 
wwhitney said:
I guess this is the main counterargument, that the language in 210.11 contrasts with the clear language in 215.2. The 210.11 language only ever discusses branch circuits in aggregate, never individually, so the requirement to supply the load calculated in 220 applies only in aggregate to the branch circuits, not to each individual branch circuit.

Cheers, Wayne
Click to expand...

Yes. You have to have so many circuits for so many recs, but nothing defines you putting a certain number of recs on a circuit.

For the earlier scenario, 3 circuits. so many recs on each circuit, does not matter how you divide them up.

If you plug in a 2400w load into each circuit, each load is served.
 
Jamesco said:
NO. That is a minimum for figuring the calculated load (220.14(I)

Go to table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle.

Circuit Rating, amps........ Receptacle Rating, amps.......... Maximum Load,
15 or 20 ...................................15 ................................ 12 amps
20 ...........................................20 ................................. 16 amps
Click to expand...

So plug one 16A load into each of my circuits through one receptacle and I am good.;)
 
jumper said:
Nothing says a max of 13 either.

2 circuits for 15 recs, i can put 14 on one and 1 on the other.

my two circuits provide the power for the required load calculation.
Click to expand...

NO.

13 X 180VA = 2400VA, 20 amps.

If you have 15 duplex receptacles and you are going to have run 2 branch circuits, why wouldn't you install 8 on circuit, and 7 on the other circuit?
 
Jamesco said:
NO.

13 X 180VA = 2400VA, 20 amps.

If you have 15 duplex receptacles and you are going to have run 2 branch circuits, why wouldn't you install 8 on circuit, and 7 on the other circuit?
Click to expand...
Because I might know that one of the circuits is for a particular heavy load and the rest are purely convience recepts.

I might have limited wall space in one room.

I might just be plain nuts, but there's nothing in the code that stops me from going over a certain number of recepts on one branch circuit.
 
Jamesco said:
NO.

13 X 180VA = 2400VA, 20 amps.

If you have 15 duplex receptacles and you are going to have run 2 branch circuits, why wouldn't you install 8 on circuit, and 7 on the other circuit?
Click to expand...

Because I do not have to if I do want to. Are you now seeing my point?

I have met the requirements as written. I have enough power to serve the receptacle loads that i calculated in 220. My number of circuits satisfies 210.

How I divide up the receptacles is undefined and my choice.
 
jumper said:
So plug one 16A load into each of my circuits through one receptacle and I am good.;)
Click to expand...

Its not unusual to see 15 amp duplex receptacles spec'd for 20 amp general-purpose branch circuits in a commercial occupancy.
 
ActionDave said:
Because I might know that one of the circuits is for a particular heavy load and the rest are purely convience recepts.

I might have limited wall space in one room.

I might just be plain nuts, but there's nothing in the code that stops me from going over a certain number of recepts on one branch circuit.
Click to expand...

I am nuts, you are crazy. Get it straight dude.
 
Jamesco said:
I found an Email for contacting Mike Holt. I am going to send him an email tomorrow with a Link to this thread and ask him for a ruling on 220.14(I) ..
Click to expand...

1) You may propose arguments with evidence, but verdicts are not provided.
2) Code disputes are settled by AHJ's, and proposals to applicable code panels.
3) Community Forums are no-ones bully pulpit, and usually not a democracy.
4) Disputes drifting off topic, from Original Poster, are usually closed.
5) Individuals that cause threads to close have been banned for undesirable conduct.
6) Good evidence and thoughtful persuasion goes much further than piss & vinegar.
 
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