Series: Subject:
Question: 41 of 442

# Induction Motor Power Factor

A 3-phase induction motor running on 500v at full load draw 40A current at 0.85 pf Lagging if 85 micro Farad capacitor connected across its terminal than what would be a New Power Factor?
Asked by: vijendra_mits | Member Since Jan-2012 | Asked on: Jan 27th, 2012

View all questions by vijendra_mits

vishnu

Answered On : Feb 18th, 2012

--> Find the reactance offered by capacitor i.e 37.46 ohm. so leading current drawn by capacitor is 9.095A @90 deg lead.
--> Current drawn by the motor is 40A @ 31.788 deg lag.
--> Resultant current drawn by the motor is 36.047 A @19.404 deg lag
--> So, the resultant p.f of the system is cos(19.404) = 0.943 lag.

mahmoudp1

Answered On : May 1st, 2012

You didn't specify the capacitors connection is delta or star
assuming (delta)
Xc = 37.462 ;
reactive power drawn by capacitor = 6684.49 VAR
active power drawn by motor = 34641 watt
old power factor = .85 lag
new power factor = .91 lag

1 User has rated as useful.