Ay-connected of three identical 100-kva 7967/277 v transformers is supplied with power directly from a large constant-voltage bus. in the short-circuit test, the recorded values on the high- voltage side for one of these transformers are: vsc = 560 v isc = 12.6 a psc = 3300 w (a) if this bank delivers a rated load at 0.88 pf lagging and rated voltage, what is the line-to-line voltage on the primary of the transformer bank? (b) what is the voltage regulation under these conditions?

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w