Question

Three star connected loads, each of resistance 30Ω are connected in to a 415 V,

3-phase supply. Determine:
(i) The system phase voltage (ii) The phase current (iii) The line current

Answer 1

The system phase voltage is approximately 239.23 V, the phase current is approximately 7.97 A, and the line current is approximately 13.84 A.

Step-by-step explanation:

To determine the given quantities, we can use the formulas for a star-connected load in a 3-phase system. For (i) the system phase voltage, Vph = Vline / sqrt(3), where Vline is the line voltage. For (ii) the phase current, Iph = Vph / R, where R is the resistance of each load. And for (iii) the line current, Iline = sqrt(3) * Iph.

Using the given values, we can calculate:

(i) Vph = 415 / sqrt(3) ≈ 239.23 V

(ii) Iph = Vph / 30 ≈ 7.97 A

(iii) Iline = sqrt(3) * 7.97 ≈ 13.84 A