V.D Formula in NEC

[m sleem]

Can we use the NEC formula to calculate the V.D at any values of power factor other than P.F= 100%, if no how we can manage!!

 

[GoldDigger]

View attachment 7960Can we use the NEC formula to calculate the V.D at any values of power factor other than P.F= 100%, if no how we can manage!!

If you use the actual (including reactive) current in the formula, you will get the actual voltage drop, and can calculate the power dissipated in the wire. But because that drop may not be in phase with the applied voltage you will not measure the voltage at the equipment as being the applied voltage minus the voltage drop. It depends on what you need to use the voltage drop figure for.

 

[jcbabb]

View attachment 7960Can we use the NEC formula to calculate the V.D at any values of power factor other than P.F= 100%, if no how we can manage!!

In the 2011 NEC, Chapter 9, Table 9 has effective Ze for a power factor or 0.85. Note 2 below the table shows how to approximate the effective Ze for other power factors.

Ze = RxPF + Xlsin[arccos(PF)]

It is an approximation.

 

[m sleem]

Thanks for all..