Electron_Sam78
Senior Member
- Location
- Palm Bay, FL
I know there are voltage drop calculators but what's the math behind it?
How do you calculate voltage drop?
- Thread starter Electron_Sam78
- Start date
- Status
Jim Shorts
Member
- Location
- Central Florida
2 x K x L (Length) x I (current) / cmils (circular mil area of the conductor from NEC chapter 9 Table 8)
K = 12.9 for copper and 21.2 for aluminum conductors
K = 12.9 for copper and 21.2 for aluminum conductors
barbeer
Senior Member
- Location
- Pinellas County, FL
Thats alota gozintas!
The formula posted by Jim Shorts is the basic formula most often used. It's result is not highly accurate, and almost always higher than actual. All voltage drop formulas are based on Ohm's Law (E = I ? R) or the AC variation (E = I ? Z). The formula called the "exact voltage drop formula" by the IEEE is...
where cosθ is the power factor of the circuit. R and X (reactance) are determined using L and other parameters, such as the type of conduit.
Most "online type" voltage drop calculators use the basic formula.
Last edited:
Electron_Sam78
Senior Member
- Location
- Palm Bay, FL
The formula posted by Jim Shorts is the basic formula most often used. It's result is not highly accurate, and almost always higher than actual. All voltage drop formulas are based on Ohm's Law (E = I ? R) or the AC variation (E = I ? Z). The formula called the "exact voltage drop formula" by the IEEE is...
where cosθ is the power factor of the circuit. R and X (reactance) are determined using L and other parameters, such as the type of conduit.
Most "online type" voltage drop calculators use the basic formula.
Wow, no wonder calculators are popular.
- Status