# Number of circuits? *Challenge Question*



## Tangent (Mar 19, 2017)

Number of circuits required for the lighting load of an 8000 sq.ft. residence?
Any guesses? :thumbsup:


----------



## PlugsAndLights (Jan 19, 2016)

ONE! They're all 9W LEDs. What do I win? 
P&L


----------



## Majewski (Jan 8, 2016)

PlugsAndLights said:


> ONE! They're all 9W LEDs. What do I win?
> P&L


Another ct!


----------



## ralpha494 (Oct 29, 2008)

5 or 7. 25 or 6 to 4.


----------



## Bird dog (Oct 27, 2015)

Homework question Tangent?


----------



## CADPoint (Jul 5, 2007)

Tangent said:


> Number of circuits required for the lighting load of an 8000 sq.ft. residence?
> Any guesses? :thumbsup:


Table 220.12 & Table 220.42


----------



## Tangent (Mar 19, 2017)

Well this is my guess? 17
(14) 15A + (2) 20A small appliance loads + (1) 20A laundry


----------



## Tangent (Mar 19, 2017)

Bird dog said:


> Homework question Tangent?


You better believe it!:thumbsup:


----------



## Tangent (Mar 19, 2017)

PlugsAndLights said:


> ONE! They're all 9W LEDs. What do I win?
> P&L


*TELL HIM WHAT HE WINS BOB!*
A new 9w individual LED with no driver.
_*Batteries not included*_


----------



## Wiresmith (Feb 9, 2013)

zero, what no-one else lives around the amish


----------



## active1 (Dec 29, 2009)

(14) 15a
(10) 20a


----------



## backstay (Feb 3, 2011)

Tangent said:


> Number of circuits required for the lighting load of an 8000 sq.ft. residence?
> Any guesses? :thumbsup:


Zero, residence is not part of the NEC. Dwelling?


----------



## John Valdes (May 17, 2007)

hd13 said:


> zero, what no-one else lives around the amish


I heard many Amish have electricity but hide it from their bishop.
I saw it on TV......:whistling2:


----------



## joebanana (Dec 21, 2010)

Tangent said:


> Well this is my guess? 17
> (14) 15A + (2) 20A small appliance loads + (1) 20A laundry


Are required small appliance, and laundry branch ckts. part of the lighting and general use branch ckts calc.?
What about range and dryer loads?
A/C, water heater?


----------



## Barjack (Mar 28, 2010)

Tangent said:


> Number of circuits required for the lighting load of an 8000 sq.ft. residence?
> Any guesses? :thumbsup:


Remember, 'required' = 'minimum'.

I say (5) 20A or (6) 15A.


----------



## Dennis Alwon (May 9, 2009)

Tangent said:


> Number of circuits required for the lighting load of an 8000 sq.ft. residence?
> Any guesses? :thumbsup:


3 20 amp circuits-- laundry and small appliance branch circuit.

8000 x 3 = 24000

first 3000 @ 100% 3000
[email protected] 35% = 21000 x .35 = 7350

15 amp x 120 v = 1800
20 amps x 120 = 2400

7350/ 1800 = 4.08 Technically 4 circuits should work however I am not certain 220.5 would apply here so I would say 5 circuits @ 15 amps 

7350/2400 = 3.06 therefore 4 - 20 amp circuits Plus the 3 for the small app
means 

7- 20 amp circuits

or

3 - 20 amp circuits and 5 - 15 amp circuits


----------



## Barjack (Mar 28, 2010)

Dennis Alwon said:


> 3 20 amp circuits-- laundry and small appliance branch circuit.
> 
> 8000 x 3 = 24000
> 
> ...


Dennis, shouldn't you add the first 3,000 VA to whatever gets multiplied by 35%?

3,000+(21,000 x 0.35) = 10,350


----------



## Barjack (Mar 28, 2010)

I forgot about this:



> *220.42 General Lighting.* The demand factors specified in
> Table 220.42 shall apply to that portion of the total branch circuit
> load calculated for general illumination. They shall
> not be applied in determining the number of branch circuits
> for general illumination.


I wish to amend my previous post. 

Technically, only one should be required.


----------



## Dennis Alwon (May 9, 2009)

Barjack said:


> Dennis, shouldn't you add the first 3,000 VA to whatever gets multiplied by 35%?
> 
> 3,000+(21,000 x 0.35) = 10,350


Yes-- did this at 4 am or so Lying in bed just like Brian Wilson did... thanks

10350/1800=6 15 amp and 3 - 20 amp circuits


----------



## Dennis Alwon (May 9, 2009)

Barjack said:


> I forgot about this:
> 
> 
> 
> ...


I bet the test will not come up with that as an answer....LOL


----------



## active1 (Dec 29, 2009)

My bad.
Forgot the first 3000 sf 100% then remaining sf at 35% part.


----------



## sbrn33 (Mar 15, 2007)

I come up with 44.


----------

