Just the second question and with a couple of lines shown work.
Needs to be done before around 5 hours from now.
can be done by hand or by computer.
Assignment 4 – EET360 – 28 OCT 2015 DUE Monday 9 NOV 2015 – 6PM EST (Submit PDF electronically through Blackboard) Answer all questions and show all working and justification. Handwritten answers are permitted provided they are clear, organized and neat. This is an individual assignment. Please include a signed student declaration on the coversheet. Use the assignment submission checklist to make sure your submission is compliant. Non-compliant submissions will receive a zero. 1. A three-phase 220 V star connected 60 Hz six-pole 10 HP induction motor has the following circuit parameters on a per-phase basis: �” = 0.344 Ω �* = 0.147 Ω �” = 0.498 Ω �* = 0.244 Ω �1 = 12.6 Ω The friction and windage losses amount to 262 W and may be assumed constant. Core-losses are lumped into the friction and windage losses. For a slip of 2.8%, calculate a) the line current and power factor b) the shaft torque (in Newton-meters and foot-pounds) and output horsepower c) the efficiency d) the starting torque (in Newton-meters and foot-pounds) e) the maximum torque (in Newton-meters and foot-pounds) that the motor can develop and the speed at which this occurs. 2 2. A three-phase induction motor has the following nameplate data: RATING 22 kW VOLTAGE 415 V POLES 6 CURRENT 33.3 A SPEED 971 rpm CONNECTION DELTA FREQUENCY 50 Hz DESIGN CLASS B When tested, the following No-load, Locked Rotor, and dc resistance test results were recorded: NO LOAD TEST (at rated frequency and voltage) �45 = 415 V �45 = 8.9 A �45 = 800 W LOCKED ROTOR TEST (at reduced frequency 12.5 Hz) �5< = 30 V �5< = 33.3 A �5< = 1211 W RESISTANCE TEST Stator line-to-line resistance measured as �5=5 = 0.220 Ω If the friction and windage loss is 412 W, determine: a) the per-phase equivalent circuit of the induction motor for full-load speed (draw the circuit with impedance values listed next to each component) b) the slip at which maximum torque occurs; c) the output torque (in Newton-meters and foot-pounds) at full load. 3 3. A three-phase induction motor has the following nameplate data: Using the data given in the nameplate, determine the following and justify fully your answers? a) How many poles does this motor likely have? Why? b) What is the synchronous frequency of this motor? c) What is the slip at rated load for this motor? d) What is the expected maximum starting current (inrush) for this motor? e) What is the input power supplied if we assume the motor is operating at its nominal efficiency with rated nameplate values? f) What is the rated output torque for this motor? g) What is the input reactive power (Q or VA-reactive) drawn from the supply under rated conditions (hint: use the given power factor value which is the nominal power factor under rated load) ?