Description : Is the ship's alternator Star wound or Delta wound?
Last Answer : Refer Dennis T Hall
Description : What is star / delta ?*
Last Answer : In star VL = √3 VΦ In delta VL = VΦ
Description : Is the alternator connected star or delta
Last Answer : Look up in Dennis T Hall. Also in your ship ask E/O. Normally star.
Description : What is the meaning of Star winding/ Delta winding?
Description : Can you guys explain the advantages of frequency converter against the star delta or soft starter?
Last Answer : ¬Soft starters A soft starter is, as you would expect, a device which ensures a soft starting of a motor. A softstarter has different characteristics to the other starting ... at rated current from zero to full speed. Frequency converters are becoming cheaper all the time.
Description : Where is a rotor wound AC motor used?
Last Answer : For starting heavy torques, mostly used on portable machines and small winches.
Description : Please ripley me due to emergency
Last Answer : To calculate the flux density in the ring, you need to use the following formula: B = (μ * I * N) / (2 * π * r) where: B is the flux density in the ring (in teslas) μ is the relative permeability ... 2 * π * 0.127 m) = 0.53 T So the flux density in the ring would be approximately 0.53 teslas.
Description : Disadvantages of Star-Delta Starting of Induction motor?
Last Answer : In Star-Delta starting induction motor stator is connected in star connection for starting after picking up speed it is connected to delta connection. When induction motor is connected in star connection ... . This also results in reduced starting torque (1/3 times compared to delta connection).
Description : What are the advantages of star-delta starter with induction motor?
Last Answer : The main advantage of using the star delta starter is reduction of current during the starting of the motor. Starting current is reduced to 3-4 times of current of Direct online starting Hence the starting current is reduced , the voltage drops during the starting of motor in systems are reduced
Description : Why star delta starter is preferred with induction motor?
Last Answer : Star delta starter is preferred with induction motor due to following reasons: Starting current is reduced 3-4 times of the direct current due to which voltage drops and hence it causes less ... caused. In addition, starting torque is increased and it prevents the damage of motor winding.
Description : Develop the control circuit for star-delta starter used for starting a 3 ∅ induction motor.
Last Answer : Control Circuit for Star-Delta Starter: 1) Automatic Star-Delta Starter: OR 2) Semi- automatic Star-Delta Starter:
Description : Draw and explain star delta starter for 3 phase induction motor
Last Answer : Star Delta Starter for 3 Phase Induction Motor: Diagram Explanation: The stator winding of the motor which is designed for delta operation is connected in star during starting ... which connects stator windings in delta connection. Now each stator phase gets full line voltage VL.
Description : Describe the power and control circuit for automatic Star-Delta starter for 3-phase induction motor.
Last Answer : Power circuit: Control circuit:
Description : Consider the following statements: Star delta starter is used in 3-phase induction motor because it 1. Prevents heating of the motor winding 2. Ensures permissible minimum starting current 3. Is regulated by electricity ... and 4 are correct (c) 1, 3 and 4 are correct (d) 1 and 2 are correct
Last Answer : Consider the following statements: Star delta starter is used in 3-phase induction motor because it 1. Prevents heating of the motor winding 2. Ensures permissible minimum starting current 3. Is regulated by ... and 4 are correct (c) 1, 3 and 4 are correct (d) 1 and 2 are correct
Description : Which of the following procedures should be used to determine the load of a threephase, delta wound, AC generator? A. Multiply the amperage in one phase by three. B. Divide the total amperage in all ... square root of three. D. Divide the total amperage in all phases by the square root of three.
Last Answer : Answer: C
Last Answer : Stepper Motor Such One Kind of Motor Which Equal In the corner Rotation Generated By To whom Step To say Is Since Step by step Step by step Equal In the corner Rotation Creation By So This one Stepper Motor Says.
Last Answer : that Motor AC And DC Both Supply A. Let's go Him Universal Motor Says.
Description : What are the differences between synchronous and induction motor?*
Last Answer : Synchronous motor : Constant speed on all loads, can be operated on a wide range of power factors, not self starting, requires dc excitation.
Description : What can be possible reasons for a motor failing to start?
Last Answer : No power , Fuse blown , Overload trip, contactor coil burnt , Contactors contacts bad, control circuit relay faulty, stop switch open circuit and start switch does not operate, hold on contact does not make and motor burnt
Description : How can the direction of rotation of an AC motor be reversed?*
Last Answer : By interchanging any two supply lines.
Description : What are the basic parts of a DC motor?*
Last Answer : Rotor and stator, field poles, commutator, brushes, fan impeller, bearing & housing, end covers and name plate.
Description : Explain what happens if a DC motor is fed with AC supply
Last Answer : Motor will run at low speed, sparking at brushes, heat due to eddy current will finally burn the motor.
Description : How is the speed of a DC motor varied?
Last Answer : To vary the speed of a DC motor we need a constant voltage power supply with a series POT resistor of higher watt rating. A Pulse Width Modulator (PWM) can be used.
Description : How is the speed of a 3-phase induction motor varied?
Last Answer : The speed of a normal 3-phase induction motor is a function of the frequency of the supply voltage. Changing the speed of such a motor hence requires building a 3-phase power frequency ... realised by using power MOSFETs (or IGBTs) capable of handling high voltages and fast switching speeds.
Description : What is a synchronous motor?
Last Answer : A constant-speed motor, the speed being dependent on the frequency of the ac supply and the number of poles for which it is designed.
Description : What is an induction motor?
Last Answer : An induction motor is an alternating current motor in which the primary winding on one member (usually the stator) is connected to the power source and a secondary winding or a squirrel-cage secondary winding on the other member (usually the rotor) carries the induced current
Description : Why are motor ratings given in KW and that of alternator and transformer given in KVA?
Last Answer : kW is the output mechanical power of a motor and is expressed in kW. kVA is the net (apparent) power input to the transformer. This input power is the output + losses. kW = kVA x system power factor
Description : Which of the following converts electric energy into mechanical energy: a. Transformer b. DC generator c. Motor d. AC generator
Last Answer : d. AC generato
Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field
Last Answer : d. gravitational field
Description : The most common source of AC voltage is: a. motor b. generator c. cell d. transformer
Last Answer : c. cell
Description : The application of mutual induction is: a. TV b. Radio c. Transformer d. Motor
Last Answer : c. Transformer
Description : When a motor is just started, back emf is almost ______: a. Infinite b. zero c. minimum d. maximum
Last Answer : d. maximum
Description : If the motor is overloaded, then the magnitude of ‘back emf’” a. Increases b. Decreases c. Constant d. Becomes zero
Last Answer : Increases
Description : State the need of energy conservation in electrical motor.
Last Answer : Need of energy conservation in Electrical motors: 1. Induction motors are used as electrical drives in industrial, commercial and residential sectors. 2. Considering all industrial applications, 70% of ... system. 8. To adopt advanced technology in design and to use better quality materials.
Description : Describe the following energy conservation methods of electrical motor. i) By motor survey ii) By matching loads with motor rating
Last Answer : Energy conservation methods of electrical motor: 1) By Motor Survey: Large industries have a massive population of LT motors. Load survey of LT motors can be taken-up methodically to ... -speed motors, eddy-current couplings, fluid couplings, and solid-state electronic variable speed drives.
Last Answer : Singer Refrigerator And Walton Refrigerator Electricity Affordable 3
Description : Sometimes, when you change the running direction of a E/R blower (from supply to exhaust) it trips. Why?
Last Answer : If the flaps of the blower are not set or opened properly or the filters are clogged, the air supply is affected and the blower may be overloaded causing it to trip. Ask E/O for more information.
Description : How does this cause a rotation to change?
Last Answer : Due to the change in phase sequence, the rotating magnetic field changes direction and the rotor rotates in the opposite direction.
Description : The deformation of body is the change in its a) Shape b) Length c) Area d) All of above
Last Answer : d) All of above
Description : A magnetic field acts on a charged particles so as to change its: a. speed b. energy c. direction of motion d. all of these
Last Answer : Only direction of motion will change ...it means velocity will change but speed same
Description : “The direction of induced current is always so as to oppose the change which causes the Current” is the statement of: a. Faraday’s law b. Lenz’s Law c. Ohm’s Law d. Kirchoff’s rule.
Last Answer : c. Ohm’s Law
Description : The phenomenon of producing emf in the coil due to change of current in the coil itself is called: a. mutual induction b. self-induction c. self-inductance d. mutual inductance
Last Answer : d. mutual inductance
Description : The induced emf is produced in a circuit due to: a. Initial magnetic flux b. final magnetic flux c. Change of magnetic flux d. constant magnetic flux
Last Answer : d. constant magnetic flux
Description : Which of the following quantities change when a proton moves at right angles to a magnetic field? a) Momentum b) Energy c) Speed d) All of these
Last Answer : a) Momentum
Description : ___________ is not affected by a magnetic field a) Change in magnetic flux b) a moving electron c) a stationary proton d) current flowing in a conductor
Last Answer : c) a stationary proton
Description : The fractional change in resistance per kelvin is known as, a. temperature coefficient of resistance b. coefficient of Voltage of charge c. thermal expansion d. all of above
Last Answer : a. temperature coefficient of resistance
Description : Write the formula from Star to Delta ?
Last Answer : Answer : Dividing the product of the resistors connected to the star by dividing the resistors of the opposite arm by taking two together, the quotient is equal to the value of each resistor connected.
Description : What equipment are star delta starters used in?
Last Answer : Star Delta starter is used to start the AC motors with rating generally higher than 11 kw, depending upon the type of load.
Description : If P is the power of a star connected system then what will be power of an equivalent delta connected system? A..P B. 3P C. P/3 D. None of the above
Last Answer : Ans: A
Description : What advantage has the star connection over the delta connection ?
Last Answer : A. Each star connection transformer is wound for only 57.7% of line voltage . In hv transmission, this admits of much smaller transformer being built for high voltage than possible with delta connection, because of less insulation.