Download What will happen when when armature winding of a dc shunt motor

What is the difference between a DC motor and ac motor?
Answer:
D.C motor works on direct current. and by changing its polarity we can change the
direction of motor shaft. where in A.C motor this all not happening it and it works on
alternative current
Difference between ac motor and dc motor?
Answer:
Direct current or DC electric motors work for situations where speed needs to be
controlled. DC motors have a stable and continuous current. DC motors were the
first and earliest motors used. They were found, however, to not be as good at
producing power over long lengths. Electric companies found using DC motors to
generate electric did not work because the power was lost as the electric was
transmitted. Brush DC motors use rings that conduct the current and form the
magnetic drive that powers the rotor. Brushless DC motors use a switch to produce
the magnetic drive that powers the rotor. Direct current motors are often found in
appliances around the home.
Alternating current or AC electric motors are used differently based on what type of
AC motor it is. Single phase AC motors are known as general purpose motors. They
work well in many different situations. These AC motors work great for systems that
are hard to start because they need a lot of power up front. Three phase, also called
polyphase, AC motors are usually found in industrial settings. These motors also
have high starting power built transmit lower levels of overall power. AC power gets
its name from the fact that it alternates in power. The amount of power given off by
an AC motor is determined by the amount of power needed to operate the system.
Difference between DC motor and AC generator?
Answer:
Let me tell you what does each word means:
Motor: is a device which converts electrical energy(Voltage/Current) into mechanical energy
(eg: rotating shaft)
Generator: is a device which converts mechanical energy (eg: rotating shaft) into electrical
energy(Voltage/Current).
DC: electricity in which voltage has constant polarity and current flows in same direction.
AC: electricity in which voltage switches polarity (+ve to -ve & vice versa) and current flows
backforth (Changes direction periodically)
An AC generator can act as an AC motor (ie what is called "motoring", and is undesireable in
the power industry).
The most obvious difference between what you're asking is their purpose as the prevous
answerer points out. Second is one uses AC vs. DC., which effects the physical makeup of
the device. There are many more, but I will stop with three - a DC motor's speed is variable /
not constant, while AC generators are typically spun at "synchronous" speed, and kept there.
What is the difference between dc motor and dc shunt motor?
]
Answer:
D.C. motors are categorised according to the way in which the field winding is connected in
relation to the armature winding. The term 'shunt' is an archaic word for 'parallel', so a d.c.
'shunt motor' is one in which the field winding is connected in parallel with its armature
winding. Another category is the d.c. 'series motor', in which the field winding is connected
in series with the armature winding. Yet another category is the d.c. 'compound motor', in
which there are two field windings; one in parallel, and the other in series, with the armature
winding. Each of these connections gives a d.c. motor a different operating characteristic,
making them suitable for different types of load.
What is difference between stab shunt dc motor and shunt dc motor?
Answer:
A Stab-Shunt wound motor is a type of compound motor. Is has a field in series with the
armature and also a field in parallel (shunt).
You can tell the difference between the leads as the field in series with the armature has to be
able to handle the amperage load of the armature itself. It will have leads identical in size to
the armature.
The key issue to watch for is wiring the shunt and the series field in opposition to each other.
This will create a differentially wound motor (suicide motor). The fields will (in effect) offset
each other as speed/current increases. The faster it rotates, the more the series field will
cancel the shunt field. This is DC motors 101, less field = faster rotation. This can cause a
runaway motor.
What is difference between shunt series dc motor?
Answer:
field winding is connected in series with armature
DC shunt motor application?
Answer:
centrifugal pumps
What are the applications of a DC shunt motor?
Answer:
Dc shunt motor is a constant flux and constant speed motor . So that it is used in centrifugal
pumps ,machine tools ,blowers and fans etc.
What is the application of dc shunt generator?
Answer:
dc shunt motor is used where constant speed is required.
Applications of a dc shunt generator?
Answer:
1.for lightening purposes
2.for battery chargings
3.for electroplating
What are the characteristics of dc shunt generator?
Answer:
The open-circuit characheristics and the load characheristics
Why you perform open circuit characteristics of a dc shunt generator?
Answer:
to find the relation between emf generated and Field current .....
What will happen when shunt field is kept open when generator is running in a
dc shunt generator?
Answer:
n=emf/flux according to this formula field open means flux
will be zero.flux zero means speed will be infinity,but we
know that no machine can't reach infinite speed so that
therotically ok but practically starting speed will
increase then it will reduced zero.
What will happen if the field of a DC shunt motor is opened under running
condition?
Answer:
Typical applications; "the motor will have a limited amount of torque, lesser in value than
what is needed for normal operation. Thus, is real world workings the unit will overload,
stop, not work, trip OL.
What will happen when field winding of dc shunt motor is disconnected?
Answer:
when the field winding of dc shunt motor is disconnected, the armature takes full line current
and it runs very high speed
What will happen when when armature winding of a dc shunt motor is
disconnected?
Answer:
In D.C Shunt motor, the field winding is connected parallel with the armature winding.. If
you remove the supply to armature winding, the motor will stop after some time.
What are field windings and armature windings in a dc motor and generator?
Answer:
field winding is for producing magnetic field (flux) both in DC Motor and DC Generator.
EMF is induced in armature winding of DC Generator which finally gives power supply/load
current to electrical load circuit (lamp, fan etc.). Power supply is fed to Armature winding in
a DC Motor to produce torque for running the motor.
What Three types of windings are used on dc generator armature?
Answer:
Shunt, series, and compound windings.
Which type of dc armature winding requires equalizer rings?
Answer:
Certain "Lap" wound armatures.
Armature reaction in a DC generator?
Answer:
ARMATURE REACTION in DC Machine
All current-carrying conductors produce magnetic fields. The magnetic field produced by
current in the armature of a dc generator affects the flux pattern and distorts the main field.
This distortion causes a shift in the neutral plane, which affects commutation. This change in
the neutral plane and the reaction of the magnetic field is called armature reaction.
In a dc generator brushes are placed in which side to avoid armature reaction?
Answer:
along the M.N.A axis
along the M.N.A axis
In a DC generator if the brushes are given a small amount of forward shift the
effect of armature is?
Answer:
is fully diamagnetism
Why do armature resistance is low in dc generators?
Answer:
Because it is made of pure wire with nothing beyond its length and interaction with its neigh
boring wires to create resistance
Why the value of armature resistance is low?
Answer:
because it depends inversely to speed
How do you measure armature resistance practically?
Answer:
by using measuring meter
Why armature resistance is maximun in motors?
Answer:
avoid high stating currents
Why external resistances are added to armature circuit in a dc motor?
Answer:
extra resistance is added in order to decrease starting current and improve starting torque
Why is the armature rheostat of dc motor kept at maximum resistance
position?
Answer:
to limit the high current
Why motor rheostat kept minimum position generator rheostat maximum
position?
Answer:
the back emf increases so that high currents doesn't pass through the field windings
Why rheostat position kept in minimum position in shunt motor load test
experiment?
Answer:
it is kept at minimum position to produce more torque which is required for starting a motor
What is swinburne's test of dc shunt motor?
Answer:
swinburne's test on dc shunt machine is to predetermine the efficiency of the dc machine , but
it is not accurate it is just like estimation of efficiency of dc shunt machine when it is run as a
motor and a generator............................
Why is Swinburne's test done on dc machines?
Answer:
because we cannot apply to series motor
Why swinburne's test cannot be performed on series machine?
Answer:
This is a no load test and so it cannot be performed on series machine
How can Swinburne's test be adopted for series motor?
Answer:
the method can not be used in the case of a d.c series motor
What is Swinburne's test?
Answer:
For a d.c shunt motor change of speed from no load to full load is quite small. Therefore,
mechanical loss can be assumed to remain same from no load to full load. Also if field
current is held constant during loading, the core loss too can be assumed to remain same.
In this test, the motor is run at rated speed under no load condition at rated voltage. The
current drawn from the supply IL0 and the field current If are recorded. Since the motor is
operating under no load condition, net mechanical output power is zero. Hence the gross
power developed by the armature must supply the core loss and friction & wind age losses of
the motor.
The biggest advantage of Swinburne's test is that the shunt machine is to be run as motor
under no load condition requiring little power to be drawn from the supply; based on the no
load reading, efficiency can be predicted for any load current. However, this test is not
sufficient if we want to know more about its performance (effect of armature reaction,
temperature rise, commutation etc.) when it is actually loaded. Obviously the solution is to
load the machine by connecting mechanical load directly on the shaft for motor or by
connecting loading rheostat across the terminals for generator operation. This although
sounds simple but difficult to implement in the laboratory for high rating machines (say
above 20 kW), Thus the laboratory must have proper supply to deliver such a large power
corresponding to the rating of the machine. Secondly, one should have loads to absorb this
power.
What are the advantages of Swinburne's test?
Answer:
we can predetemine the efficiency of a dc machines working as a motor or generator
What are the advantages and disadvantages of Swinburne's method?
Answer:
Everything has its advantages and disadvantages both,
so accept these logics and their aspects in your life.
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Answer:
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Answer:
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