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How many duplex receptacles can you put on one circuit?

jar546

jar546

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First of all, this is for a commercial use property whether it be offices, or an employee break room, etc. This is not a question for dwelling units.

If there are no planned loads such as appliances, or other loads, how many general use, duplex receptacles can you put on a single 20A - 120v circuit?

Hint: NEC 220.14
 
The NEC does not give a number. The NEC gives a direction for you to follow. Rounding down results in thirteen. Ten is better. Every situation has it's own requirements. My favorite electrician would make every dwelling kitchen counter receptacle a home-run.... and that was fifty years ago.
 
ICE said:
The NEC does not give a number. The NEC gives a direction for you to follow. Rounding down results in thirteen. Ten is better. Every situation has it's own requirements. My favorite electrician would make every dwelling kitchen counter receptacle a home-run.... and that was fifty years ago.
Click to expand...
Is this based on maximum spacing?

I thought that if a room had receptacles on a 15 amp breaker, satisfied the watts per sf, and satisfied the spacing requirements, you could add as many additional receptacles as you wanted. Instead of 12', why not 6'? Would seem safer because your lessening the use of plug strips, cube taps, and extension cords - all more likely to become a hazard than more duplexs in a boxes.

Never understood the local amendments that limit the number, as if in any scenario, that will limit the load or reduce the overloads. Users will somehow plug in all that they want.

Does seem today with LED and other lower power devices the problem lessening.
 
bill1952 said:
Is this based on maximum spacing?
Click to expand...
No. It is based on a calculation.
Given a power factor of 1, a single volt-ampere equals a single watt.
20amp x 120 volts = 2400 watts ..... 2400 watts / 180 volt-amperes = 13.333

220.14(I) Receptacle Outlets.
Except as covered in 220.14 (J) and (K), receptacle outlets shall be calculated at not less than180 volt-amperes for each single or for each multiple receptacle on one yoke. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than 90 volt-amperes per receptacle. This provision shall not be applicable to the receptacle outlets specified in 210.11( C)( 1) and (C)( 2)
 
ICE said:
No. It is based on a calculation.
Click to expand...
Specifically, for branch circuits other than in dwelling units.

ICE said:
Given a power factor of 1, a single volt-ampere equals a single watt.
20amp x 120 volts = 2400 watts ..... 2400 watts / 180 volt-amperes = 13.333
Click to expand...
You can leave power factor out of it. Power factor is for converting between Watts and Volt-Amps. But a 20A 120V circuit is always 2400 VA. And the load per duplex receptacle is listed as 180VA. So everything is VA, there's no Watts or Power Factor involved.

Cheers, Wayne
 
wwhitney said:
Specifically, for branch circuits other than in dwelling units.


You can leave power factor out of it. Power factor is for converting between Watts and Volt-Amps. But a 20A 120V circuit is always 2400 VA. And the load per duplex receptacle is listed as 180VA. So everything is VA, there's no Watts or Power Factor involved.

Cheers, Wayne
Click to expand...
I was merely attempting to show the correlation between volt-amperes and watts. The LCD (which includes me) tends to think in watts as opposed to VA.
 
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ICE said:
No. It is based on a calculation.
Given a power factor of 1, a single volt-ampere equals a single watt.
20amp x 120 volts = 2400 watts ..... 2400 watts / 180 volt-amperes = 13.333

220.14(I) Receptacle Outlets.
Except as covered in 220.14 (J) and (K), receptacle outlets shall be calculated at not less than180 volt-amperes for each single or for each multiple receptacle on one yoke. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than 90 volt-amperes per receptacle. This provision shall not be applicable to the receptacle outlets specified in 210.11( C)( 1) and (C)( 2)
Click to expand...
Commercial, correct? No such limit in residential, or at least in one and two family dwellings?
 
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