Answer ALL questions.
1.
Three loads of resistance 220 $\Omega$ are connected in star to a 440 V, 3 phase supply
Determine;
(a) the line voltage,
(b) the phase voltage,
(c) the phase current,
(d) the line current.
(15 Marks)
2.
Three loads of resistance 220 $\Omega$ are connected in delta to a 440 V, 3 phase supply.
Determine;
(a) the line voltage,
(b) the phase voltage,
(c) the phase current,
(d) the line current.
(15 Marks)
3.
For the same resistance load of 220 $\Omega$ in star and delta connection in questions (1) and
(2), discuss the results produced in phase current and line current.
(20 Marks)
4.
Three uniform impedance each resistance 75 $\Omega$ and inductance 0.3184 H are connected
in delta to a 415 V, 50 Hz, 3 phase supply. Determine;
(a) the line voltage,
(b) the phase voltage,
(c) the phase current,
(d) the line current.
(25 Marks)
5.
Three coils each having resistance 6 $\Omega$ and inductance, L in unit H are connected in delta, to
a 415 V, 50 Hz, 3-phase supply. If the line current is 30 A, find the value of L.
(25 Marks)
5.
Sketch a 3 phase connection system;
(a) Star-delta connection,
(b) Delta-delta connection.
(20 Marks)
