Answer to Question #158826 in Electric Circuits for Theo

Question

An installation requires 35KW and operates at a power factor of 0.45 from a 400v 3 phase supply what is the current taken by installation at the normal power factor 0.45

current taken at power factor 0.75

current taken at power factor of 0.9

Answer 1

the line to neutral (phase) voltage, $V_{LN}=400/\sqrt{3}=230.94v$

three phase power is 35Kw, single phase power $=35/3=11.6667Kw=11666.7w$

$Current , I =power/(voltage \times powerfactor)=11666.7/(230.94\times0.45)=112.26A$

current taken at power factor of 0.75$=11666.7/(230.94\times 0.75)=67.36A$

current taken at power factor of 0.9$=11666.7/(230.94\times 0.9)=56.13A$