Q2: Find the value of starting capacitance for a 250W, 120V, 50HZ single-phase motor that will place main and auxiliary winding currents in quadrature at starting. At standstill, motor input impedance through the main and the auxiliary windings are (4.5+j3.7) Q and (9.5+j3.5) Q respectively.

23. As load is increased from no load to full load on a 3-phase squirrel-cage induction motor, what happens to the ..

A 1200 kVA, 6600 volts, three-phase wye connected alternator, has an effectiveresistance of 2.5 ohms and a reactance of 12 ohms per phase. Determine the inducedemf and the torque developed by the armature when fully loaded at 0.8 leading power factor.

15. The main and auxiliary windings of a hypothetical 130-V, 60-Hz, split-phase motor have the following locked-rotor parameters: Rmw = 2.3 Ohms, Xmw = 3.0 Ohms, Raw = 9.25 Ohms, and Xaw = 8.2 Ohms. The motor is connected to a 130-V, 50-Hz system. Determine the capacitance, in microfarad, required in series with the auxiliary winding in order to obtain a 86 degrees phase displacement between the currents in the two windings. Correct Answer:  222.33

Using the 2 different 'single phase equivalent circuits' given below, the desired equations will be deducted. Equations separately for asynchronous motor powered by voltage source will be removed and the spaces given below will be written. You can also do your inference work. show it and deliver it. V1 and I1 are the RMS value of the AC phase voltage and current. All formulas (3 phase motor) will be written as a function of motor parameters and slip.

The stator resistance of a 1-phase induction motor is 2.5 ohm and its leakage reactance is 2.0 ohm. Onno-load, the motor takes 4 A at 96 V and at 0.25 lagging power factor. The no-load friction andwindage loss is negligible. Under the blocked-rotor condition, the input power is 130 W at 6 A and42 V. obtain the equivalent circuit parameters.

A three-phase induction motor used for a commercial application in Oman 50HZ runs at 584 rpm at no load and at 546 rpm at full load.    a) How many poles do this motor have? b) What is the percentage slip at full load?   c) The frequency of the rotor currents when slip is 7 % d) The frequency of the rotor currents at standstill.

h has rotor e.m.f. Speed of the induction motor and the frequency of its [970 r.p.m.; 1.5 Hz] 4. A 3-phase, 50-Hz induction motor with its rotor star-connected gives 500 V (r.m.s.) at standstill between the slip-rings on open-circuit. Calculate the current and power factor at standstill when the rotor winding is joined to a star-connected external circuit, each phase of which has a resistance of 10 2 and an inductance of 0.04 H. The resistance per phase of the rotor winding is 0.2 2 and its inductance is 0.04 H. Also, calculate the current and power factor when the slip-rings are short-circuited and the motor is running with a slip of 5 per cent. Assume the flux to remain constant. [10.67 A; 0.376; 21.95 A; 0.303] 5. Obtain an expression for the condition of maximum torque of an induction motor. Sketch the torque- slip curves for several values of rotor circuit resistance and indicate the condition for maximum torque to be obtained at starting. If the motor has a rotor resistance of…

The armature of a 400V, 6-pole, 25 Hz single-phase series motor is lap-wounded with 504 conductors Motor field winding has effective resistance and leakage reactionance are 0.06 22 and 0.05 12, respectively and has 18 turns. However, the armature winding has a leakage reactance of 0.04 12 and negligible resistance. At rated motor current of 300A, the flux per pole is 0.05 Wb, the short circuit current is 50A and the equivalent current to iron losses is 40A. Find motor speed , torque and efficiency at rated current .

give 2 impacts to the end-users per type of single-phase IM in terms of physical features, advantages and applications. Explain each impact not less than 60 words. Type of Single-Phase IM 1. Split-Phase IM 2. Capacitor-Start IM 3. Capacitor-Run IM 4. Capacitor-Start and Capacitor-Run IM 5. Shaded-Pole IM