Engineering, 25.04.2020 04:05 hanjonez
Question 5 (20 pts) The rated current of a three-phase transmission line is 300 A. The currents flowing by the line are measured with three current transformers each with ratio 250 : 5. What is the current you would measure at the secondary of each current transformer if rated current is flowing through each line. (of course the secondaries of the transformer must be part of closed circuits.) Consider the measured currents are exciting three over-current relays. Should the contacts of the relay close if rated current is circulating in the lines? If your answer is between no and yes, the current that the relay observes when rated current flows by the line must be the minimum pick-up current Ip. Hence, the tap position you should select, e. g., in the tap block of Fig. 1, must be equal o slightly greater than Ip for an over-current relay. Slightly greater when Ip is not an integer that matches the tap selection.
Answers: 3
Engineering, 04.07.2019 18:10
Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?
Answers: 3
Engineering, 04.07.2019 18:10
The higher the astm grain size number, the finer the gran is. a)-true b)-false
Answers: 2
Engineering, 04.07.2019 18:10
Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k
Answers: 2
Engineering, 04.07.2019 18:20
Most leaks in reciprocating air compressors can be detected and minimized by: (clo4) a)-detecting leakage areas using ultrasonic acoustic detector. b)-tightening joints and connections c)-replacing faulty equipment d)-all of the given options
Answers: 2
Question 5 (20 pts) The rated current of a three-phase transmission line is 300 A. The currents flow...
Mathematics, 14.10.2021 03:50
Mathematics, 14.10.2021 03:50
Business, 14.10.2021 03:50
History, 14.10.2021 03:50
Mathematics, 14.10.2021 04:00
Social Studies, 14.10.2021 04:00
Mathematics, 14.10.2021 04:00
Mathematics, 14.10.2021 04:00
Mathematics, 14.10.2021 04:00