Page 450 - Basic Electrical Engineering

Z will remain the same as the same windings are connected in star
Ph

In star connection, the line current is the same as phase current, hence, I =
L
I = 7 A.
Ph

Power factor, depends on the circuit parameters

Since both R and Z remain unchanged, the power factor will remain the same
at 0.756. Students may note that line current in a star connection is one-third

of the line current in a delta connection.

Example 4.10 A balanced star-connected load of 4 + j6 Ω per phase is

connected across a 400 V, three-phase, 50 Hz supply. Calculate line current,
phase current, line voltage, phase voltage, power factor, total power, and
reactive power.

Solution:

For star connection,

Power factor, cos ϕ = cos 56° = 0.56 lagging