A physical plant is served by a balanced \(\mathrm{Y}-\Delta\) circuit. The line voltage and phase impedance are \(V_{\mathrm{L}}=440 \mathrm{~V}(\mathrm{rms})\) and \(Z_{\Delta}=16+j 12 \Omega /\) phase. The owner wants to add a new \(Z_{\mathrm{Y}}=15-\) \(j 20 \Omega /\) phase load in parallel with the existing \(Z_{\Delta}\) load.

(a) Change the \(Z_{\Delta}\) load to a \(Z_{\mathrm{Y}}\) load and combine it in parallel with the new \(Z_{\mathrm{Y}}\) load to make a balanced Y-Y configuration.

(b) Using \(