dwelling load calculation...

[eric dolphy]

http://www.electrician2.com/practice_tests/qp972/gn14sol.html


please take a moment to clarify a dwelling load calculation...

in the example, the bathroom branch circuit (one 2-wire, 20A circuit) does not seem to figure into the net load or net computed load...

please provide the NEC reference as to rule, as well as the rationale...

he cites 210.11 C3 as explanation, but it does not seem to interpret issue...

thank you...

 

[Smart $]

210.11(C)(3) is where the circuit is required.

220.14(J)(1) is where the circuit is exempted from the load calculation.

 

[eric dolphy]

dwelling load calculation...

thank you for the reference...

the example appears in the code annex, but the last 'computed load for neutral' is added to his example as: 15285 VA/240 = 63.7 amps...

the code example uses 14550 VA/240 = 61 amps

any idea how the 15285 figure was determined?

thanks again

 

[Dennis Alwon]

There are many examples in Annex D so it would be helpful if you gave us specific info

 

[eric dolphy]

dwelling load calculation...

hello


in the 2011 NEC, on page 70-804, example D1(a)...one-family dwelling...


the electrician2.com example seems to add one line of calculations, arriving at 63.7 amps (computed load for neutral), whereas the code example stops at 14550 VA / 240 V = 61 amps...


thank you...

 

[Smart $]

thank you for the reference...

the example appears in the code annex, but the last 'computed load for neutral' is added to his example as: 15285 VA/240 = 63.7 amps...

the code example uses 14550 VA/240 = 61 amps

any idea how the 15285 figure was determined?

thanks again

hello


in the 2011 NEC, on page 70-804, example D1(a)...one-family dwelling...


the electrician2.com example seems to add one line of calculations, arriving at 63.7 amps (computed load for neutral), whereas the code example stops at 14550 VA / 240 V = 61 amps...


thank you...

The Code example floor area is 1500ft² (5100VA).
The electrician2.com example is 2200ft² (5835VA).
5835-5100=735=15,285-14,550

 

[eric dolphy]

dwelling load calculation...

yes, indeed...

('and, pay attention, Eric')...

it appears electrician2.com did manage to add a line which had no bearing upon the calculation: Total: 14550 just prior to the correct 15285 VA figure...

thanks again for perseverance...