A commercial Building, 60hz, Three Phase System, 230V with total highest Single Phase Ampere Load of 1,088 Amperes, plus the three-phase load of 206Amperes including the highest rated of a three-phase motor of 25HP, 230V, 3Phase, 68Amp Full Load Current. Determine the Following through showing your calculations. The Size of THHN Copper Conductor (must be conductors in parallel, either 2 to 5 sets),TW Grounding Copper Conductor in EMT Conduit. b. The Instantaneous Trip Power Circuit Breaker Size c. The Transformer Size d. Generator Size

A commercial Building, 60hz, Three Phase System, 230V with total highest Single Phase Ampere Load of 1,088 Amperes, plus the three-phase load of 206Amperes including the highest rated of a three-phase motor of 25HP, 230V, 3Phase, 68Amp Full Load Current. Determine the Following through showing your calculations. The Size of THHN Copper Conductor (must be conductors in parallel, either 2 to 5 sets),TW Grounding Copper Conductor in EMT Conduit. b. The Instantaneous Trip Power Circuit Breaker Size c. The Transformer Size d. Generator Size

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter34: Motor Installation

Section: Chapter Questions

Problem 6PP: A 350-HP squirrel-cage induction motor is connected to a 480-volts three-phase feeder. The nameplate...

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A commercial Building, 60hz, Three Phase System, 230V with total highest Single Phase Ampere Load of 1,160 Amperes, plus the three-phase load of 201Amperes including the highest rated of a three-phase motor of 20HP, 230V, 3Phase, 54Amp Full Load Current. Determine the Transformer and Generator Size.
A 3-phase, 20 MVA, 1IkV, star-connected generator is protected by the current balancing system of protection. If the ratio of the current transformer is 1,200/5, the minimum operating current of the relay is 0.75 ampere and the neutral point earthing resistance is 6 ohms, calculate, the percentage of each phase of the stator winding which is unprotected against earth faults when the machine is operating at normal voltage. Show quantitatively. the effect of varying neutral earthing resistance [say R = 3 ohm and 12 ohm].
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