Need advise..!!!

[m sleem]

I design the electrical system for a new building. Normally the power factor for any commercial building will not go beyond 0.8 (before correction). I'm planing to reach 0.93 p.f (in practical the correct way to improve power factor is coming from the actual readings). My simple question, in voltage drop calculation, which pf has to be considered (before or after improving)?

I believe we would use the improved pf but who can guarantee that while in actual working.

 

[kwired]

voltage drop is a design issue not a code issue. If you want worst case scenario then calculate your VD according to highest anticipated load conditions, which may include poor power factor.

 

[beanland]

Branch, Feeder, Service

Branch, Feeder, Service

Since the power factor is only better from the location of the shunt capacitors toward the utility, the correct current to use will depend upon where you are calculating the voltage drop. If the power factor correction occurs at the main switchboard, only the power factor from the switchboard to utility is improved. Thus, uncorrected current needs to be used on feeders and branch circuits.