Number of outlets allowed on one circuit for office

[Stevenfyeager]

How many outlets can be on one 20 amp circuit for an office ? I was always taught 13. Bec 13 x 180 va each receptacle = less than 2400 va. Thanks.

 

[480sparky]

180 va per is for calculations.

What gets plugged in / attached to the circuit will determine the number.

 

[Coppersmith]

If each office cubical has a computer, printer, desk lamp, telephone, and foot heater then one quad receptacle per circuit.

 

[infinity]

How many outlets can be on one 20 amp circuit for an office ? I was always taught 13. Bec 13 x 180 va each receptacle = less than 2400 va. Thanks.

Mike Holt says 13.

StackPath

 

[480sparky]

Mike Holt says 13.

Plug in 26 coffee machines and let 'em rip. Report back.

 

[LarryFine]

Mike Holt says 13.

Is that for load calcs or actual wiring?

 

[ActionDave]

Is that for load calcs or actual wiring?

He thinks it's for wiring.

 

[Beaches EE]

For general-purpose commercial receptacle outlets it's 13 per 20 A circuit. If the actual load is known, then design and wire for the load.

 

[480sparky]

Mike Holt says 13.

StackPath

220 is for Branch-Circuit, Feeder and Service Load Calculation. The reference 220.14(I) specifically states this is for calculation.

Receptacle Outlets. Except as covered 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....

 

[FionaZuppa]

Receptacle Outlets. Except as covered 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....

What does "single or multiple receptacle" mean? As in 1 on one yoke vs 2-3-4-5 tied together on one yoke? Is there such a thing as a NEMA 2+ yoke? Should the word "multiple" just be "dual"?

 

[480sparky]

..... Is there such a thing as a NEMA 2+ yoke? ....

Yes.

 

[LarryFine]

Triplex receptacles have been around for a while:




But, why stop there?

 

[LarryFine]

I could imagine an office building constructed in such a way that the hallways could be designed with a total of more than thirteen receptacles, say for vacuuming use, and it was decided a single circuit could serve all of them.

 

[FionaZuppa]

Ok, many on one yoke, like this pic.
But, why then say "single or multiple receptacle", why not just "per yoke" w/o changing the title of "how many receptacles on ckt", this way the "per yoke" is bound to being frame that carries the receptacles. And yes, both are equivalnet by words, I just think "per yoke" seems more fitting since it describes all of the recepts that may or may not be on the yoke.

 

[Beaches EE]

Now a power strip is another thing altogether. What is plugged into receptacle outlets does not count toward the number of receptacle yokes/straps allowed on a circuit.

 

[Dennis Alwon]

Now a power strip is another thing altogether. What is plugged into receptacle outlets does not count toward the number of receptacle yokes/straps allowed on a circuit.

No but there is nothing to stop people from plugging in electric heaters. I am one who accepts the 13 receptacle rule as the limit on a 20 amp circuit. With the number of things that gets plugged in at offices, IMO 13 is more than you would want anyway.

 

[FionaZuppa]

Now a power strip is another thing altogether. What is plugged into receptacle outlets does not count toward the number of receptacle yokes/straps allowed on a circuit.

I was just noting the strip is basically one yoke. What if the outlet was just a jbox for a hard wired strip? The strip then becomes what, "equipment"?

And btw, the MH diagram is not correct. Words do matter. That pic shows 26 receptacles on 13 yokes (2 per yoke, aka duplex recept). The correct words should be "13 strapped duplex receptacles".

And, the calculation being used appears to be "per yoke", which is why the other verbiage says "single or multiple receptacles". So in essence, per yoke seem to be the better word to use.

 

[Beaches EE]

Very true Dennis. One of the battles we fight consistently is folks plugging extension cords into outlets, then power strips into an extension cord. This can create overloads and does not make the Fire Marshal very happy. For general use outlets such as the "vacuum cleaner in the hallway", the 13 limit makes sense. For cubicles and other special purpose areas, we design to the intended loads.

 

[Dennis Alwon]

I was just noting the strip is basically one yoke. What if the outlet was just a jbox for a hard wired strip? The strip then becomes what, "equipment"?

Here is the nec rule for multioutlet assembles

(H) Fixed Multioutlet Assemblies. Fixed multioutlet assemblies
used in other than dwelling units or the guest rooms or
guest suites of hotels or motels shall be calculated in accordance
with (H)(1) or (H)(2). For the purposes of this section,
the calculation shall be permitted to be based on the portion
that contains receptacle outlets.
(1) Where appliances are unlikely to be used simultaneously,
each 1.5 m (5 ft) or fraction thereof of each separate and
continuous length shall be considered as one outlet of
not less than 180 volt-amperes.
(2) Where appliances are likely to be used simultaneously,
each 300 mm (1 ft) or fraction thereof shall be considered
as an outlet of not less than 180 volt-amperes.

 

[FionaZuppa]

Here is the nec rule for multioutlet assembles

Those rules are based on length of the yoke? What if two strips are daisy chained with the cord or hardwired interconnect being 8ft?