A phase sequence is an order or sequence in which the currents or voltages of different phases attain their maximum values. In a three-phase system, there are only two possible phase sequences: R-Y-B (positive Phase Sequence) and R-B-Y (Negative Phase Sequence).
This type of motor is designed to operate with the start winding and it’s series capacitor permanently connected to the supply. lt has two capacitors connected in parallel in the start winding circuit for starting purposes. The running capacitor is employed to correct the power factor. As a result, this motor has a higher starting torque as well as a higher efficiency. These motors are employed in sizes ranging from 375 W to 7.5 kW. The power factor of these motor is upto 80% to 100%.
Average speed:- The distance covered between two stops divided by the actual time of the run is known as average speed. Average speed = (Distance between stops)/(Actual time of run) Schedule speed:- It is defined as the ratio of distance covered between two stops and the total time of run including the time of the stop. Schedule speed = (Distance between stops) /(Actual time of run + Stop time) This shows that schedule speed is always smaller than the average speed. The difference is large in the case of urban and suburban services and is negligibly small in the case of main-line service.
The melting point of Eureka is 1221 to 1300 °C The melting point of Kanthal is 1,425 °C The melting point of Nichrome is 1400 °C The melting point of Graphite is 3,600°C Hence Eureka has the least range of temperature.
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