AC Voltage Drop 1

[dougjl]

Can anyone tell me if there is a chart anywhere that can that provides AC voltage drops? I have a 300' pull to a 125 HP motor and want to make sure that the voltage drop will not be a problem. Thanks in advance!

 

[resqcapt19]

There is an online voltage drop calculator at:

http://www.electrician.com/

However, because the NEC requires that the motor branch circuit conducotrs have an ampacity of at least 125% of the full load current in Table 430-150, it takes a very long run before the voltage drop becomes a problem. If your motor is 3 phase 460 volt it will have a FLA of 156 amps and require a minimum conductor ampacity of 195. A 3/0 copper with a 156 amp load and 300' run would give you a 1.3% voltage drop.
Don(resqcapt19)

 

[jbartos]

Suggestion: Reference:
1. IEEE Std 141-1993, "IEEE Recommended Practice for Electric Power Distribution for Industrial Plants," e.g. Table 3-12 on page 100
2. Check with larger manufactures of cables and wires, e.g.

http://www.generalcable.com