Conductor Sizing for continuos load and voltage drop

[manuelparedes]

NEC Article 210.19(A) (1) requires to size the branch circuit conductor considering continuos load, before the application of any
adjustment or correction factors. In order to size the conductor for the voltage drop, Do I have to use the continuos load curent value, or the actula load current value without increasing the 125% factor?

 

[charlie b]

First, voltage drop is not a player in the "adjustment or correction factors" mentioned in that article. We "adjust" for more than 3 current carrying conductors in a raceway. We "correct" for ambient temperatures over 30C.

That said, you can use the full load current, without adding 25% for continuous loading, when you perform a voltage drop calculation.

 

[BAHTAH]

voltage drop

voltage drop

Voltage drop would not be a consideration in your calculation. The adjustment factors of 210-19(A) are NEC requirements. There is no code requirement for voltage drop. The NEC does not consider voltage drop to be a safety issue. That being said the FPN will tell you 3% branch and 5% for branch and feeder combined as being reasonable for the proper operation of most equipment.

 

[dahualin]

Voltage drop would not be a consideration in your calculation. The adjustment factors of 210-19(A) are NEC requirements. There is no code requirement for voltage drop. The NEC does not consider voltage drop to be a safety issue. That being said the FPN will tell you 3% branch and 5% for branch and feeder combined as being reasonable for the proper operation of most equipment.

I suspect your post is misleading people. Electrical calculation shall include not only electrical load calculation, but also available short circuit current calculation, voltage drop calculation etc. Although voltage drop is not a safety issue, it is still very important. If we design and install wiring without voltage drop calculation, the associated equipment may not be able to work properly. It is also a failure of electrical system.

 

[bbrizzee]

Electrician

Electrician

Do you have a state code as well?
This is what is stated in New Mexico code ?Conductors for branch circuits shall be sized to prevent excessive voltage drop. Conductors on 15 amp branch circuits, between the overcurrent protection device and the farthest outlet served, shall not exceed 75 feet for # 14 AWG copper circuit conductors, or 150 feet for # 12 AWG copper, measured along the branch circuit conductors. Conductors on 20 amp branch circuits, between the overcurrent protection device and the farthest outlet served, shall not exceed 75 feet for # 12 AWG copper, or 150 feet for # 10 AWG copper, measured along the branch circuit conductors. Branch circuits exceeding 150 feet from the overcurrent device to the farthest outlet served measured along the branch circuit conductors, shall be sized so that the voltage drop does not exceed 5%.?