Receptacles in commercial corridor

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m sleem

Senior Member
Location
Cairo
20a receptacle located in non-dwelling corridor, the basic function for this receptacle the cleaning purposes, the vacume cleaner for such application larger than 2kw & 12 flc at 220v.
How many receptacles we can supply through 20a branch circuit?
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
If you know for a fact that the design load is over 12a then I would guess that 220.19 would limit you to one outlet but I would not be surprised to see that I am mistaken.
 

m sleem

Senior Member
Location
Cairo
If you know for a fact that the design load is over 12a then I would guess that 220.19 would limit you to one outlet but I would not be surprised to see that I am mistaken.
Fine, but i've never seen one outlet in individual circuit in corridors, at least 3 or 4 by circuit, may be one one only will be working by diversity factor, but what code says here?
 

Smart $

Esteemed Member
Location
Ohio
220.14(I) would say 180VA as a minimum.
As Gus said, if the design load is known...

However, the number of receptacles allowed on the circuit would be one at 12A ? 220V, or 2640VA, the rest at 180VA.

20A ? 220V = 4400VA

4400VA - 2640VA = 1760VA

1760VA ? 180VA = 9.7, rounded down to 9 more receptacles permitted...

...and that's only if you subscribe to the belief that the numbers of receptacles on a circuit are limited per the calculation requirements.
 

m sleem

Senior Member
Location
Cairo
As Gus said, if the design load is known...

However, the number of receptacles allowed on the circuit would be one at 12A ? 220V, or 2640VA, the rest at 180VA.

20A ? 220V = 4400VA

4400VA - 2640VA = 1760VA

1760VA ? 180VA = 9.7, rounded down to 9 more receptacles permitted...

...and that's only if you subscribe to the belief that the numbers of receptacles on a circuit are limited per the calculation requirements.
I agree your concept, but some other requirements have to be counted, voltage drop & 210.21(B)(2) says 80% of 20a.
 

Smart $

Esteemed Member
Location
Ohio
I agree your concept, but some other requirements have to be counted, voltage drop & 210.21(B)(2) says 80% of 20a.
Number of receptacles does not affect voltage drop, only what you plug into them does.

And in reality, you can't really limit the load plugged into one of several receptacles to 80% of the circuit rating. Signage is not required and may be ignored even if posted, Code itself prohibits load-limiting receptacle and plug design, and we do not post electrically-qualified, armed sentries :p
 

m sleem

Senior Member
Location
Cairo
Number of receptacles does not affect voltage drop, only what you plug into them does.
Load & length affecting the voltage drop, increasing no of receptacles leading to increasing in demand load.
Code itself prohibits load-limiting receptacle and plug design,
Would you cite me to location in code!
and we do not post electrically-qualified, armed sentries :p
That need another revolution:D
 

Smart $

Esteemed Member
Location
Ohio
Load & length affecting the voltage drop, increasing no of receptacles leading to increasing in demand load.
Yes... but there is no general Code requirement to account for voltage drop in the design.

And technically there is no voltage drop until you plug something into the receptacle and turn it on.

Would you cite me to location in code!
210.21(B)... except for 15A receptacles on a 20A branch circuit. Your OP stated 20A receptacle.
 
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