Problem 1: Three loads, each of resistance 30?, are connected in star to a 400v, 3-phase supply. Determine (A) the system phase voltage (B) the phase current (C) the line current
Problem 2: A star connected load consists of three identical coils each of resistance 30? and inductance 127.3mH. If the line current is 5.08 A, Calculate the line voltage if the supply frequency is 50Hz
Problem 3: Three identical coils each of resistance 30? and inductance 127.3mH are connected in delta to a 400V, 50Hz 3-phase supply determine (A) the phase current and (B) the line current
Problem 4: Three 12? resistors are connected in star to a 400v, 3-phase supply. Determine the total power dissipated by the resistors.
Problem 5: Three identical coils, each of resistance 10? and inductance 42mH are connected (A) in star and (B) in delta to a 400V, 50Hz, 3-phase supply determine in both star and delta :
- The phase voltage
- The impedance of each load
- The line current
- The phase current
- The power factor and phase angle
- The active (real) power
- The reactive power
- The apparent power
You should draw the power triangle to scale to represent the different quantities.