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Why rotor contactor in external resistance of slipring motor connected in delta?
Wiki User
∙ 12y ago
rotor contactor are used to cut the resistance in slip-ring motor connected through resistance box. resistance is proportional to torque. so by controlling rotor contactor resistance can be controlled and hence torque can be controlled.
for more information check torque and speed characteristic of wound motor.
Wiki User
∙ 12y ago
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How do you calcuate resistance for slipring motor?
it is related to Slip ring rotor max.currents and voltage ...
What should the value of the resistance box for a 5 hp slipring induction motor?
its depends upon rotor voltage and current
What are the functions of slip ring carbon brush external resistor in an alternalting EMF generator?
good question the use of slipring carbon brush is to give excitement to the generator , as the carbon brosh contact the rotor slip the rotaion and the speed of the generator increases we can say as an external force by anonrafee blueroz_27@yahoo.com
What is slipring motor?
Generally Slip Rings are MERCURY WETTED.The standard slip ring circuit consists of a pair of sintered metal copper/graphite brushes making contact with a brass ring.
What is the slipring used for in ac motors?
synchronous motors have a slipring to apply the dc field....Addition...to apply the excitation field to the armature/rotor that establishes the reaction with the rotating field in the stator, causing the rotor to turn the output shaft.Modern motors use a rotating transformer with stationary windings surrounding rotating windings mounted on the rotor shaft, thus eliminating the sliding contacts between the brushes and the sliprings. This improves efficiency and reliability.------- efficiency and reliability ??? ---------doing the transformer thing eliminates the need to check and change the brushes.you will still need to watch the bearings there are usually a couple brushes on the slip rings for redundancy (reliability?)There is no way possible the transformer arrangement will improve efficiencythe best tightly coupled transformers can be about 98% efficientsince this transformer must have a rather large gap so it may rotate it cannot be as closely coupled and will probably be more like 89% efficient.so at best the field with rotating transformer will be 10% less efficient than the slip rings.For a large plant the air compressors >300hp are always synchronous motorsby varying the field you can change the motor load from leading to lagging and as such save the VAR charges the power company generally tags on , easy to do with slip rings maybe not accessible with the package non slip ring motors.this of course requires monitoring the power at the service entrance and access to the exciter(s) on the large motor(s)alternators on cars have slip rings and many have a 2 wire external connection, which means the voltage is regulated on these 2 terminals, loose terminals longer wires perhaps a bad engine mount may mean the alternator will not charge the battery. without a kelvin connection there is no way the alternator can know what voltage the battery has. without a temperature sensor on the battery theres no way for the voltage to be related to the charge state. (less wire is cheaper in the short run but always less efficient)
How do you calcuate resistance for slipring motor?
it is related to Slip ring rotor max.currents and voltage ...
What should the value of the resistance box for a 5 hp slipring induction motor?
its depends upon rotor voltage and current
How do you calculate resistance box for slip ring motor?
how to calculate resistance box for slipring motors
What are the functions of slip ring carbon brush external resistor in an alternalting EMF generator?
good question the use of slipring carbon brush is to give excitement to the generator , as the carbon brosh contact the rotor slip the rotaion and the speed of the generator increases we can say as an external force by anonrafee blueroz_27@yahoo.com
Whether vfd is suitable for slip ring motors?
400hp slipring motor has been short circuited and connected to the 315kw variable frequency drive. The vfd has run continuously for 2 days without any problem.After a supply break the vfd couldnot resume but indicating a message of impedence short.
What is slipring motor?
Generally Slip Rings are MERCURY WETTED.The standard slip ring circuit consists of a pair of sintered metal copper/graphite brushes making contact with a brass ring.
How do you slipring motor is convert to inducton motor?
With a synchronous motor shorting the slip-rings together should make it work as an induction motor although perhaps not to an optimal degree.
Where is the VSS on a 1992 Chev Suburban K1500?
It located above and to the left of the differential slimjam bell housing on 1991 models but was later moved to the rear of the slipring manifold slide reset switch on 1992 models.
What happen when slip ring induction motor overloaded?
Let me give you a different yet convincing answer, as you over load the machine, it will run slow to get more induced emf in rotor, we all agree to a point that,as it slows down it will have more emf but as the electrical angle increases beyond 90, for slipring machine with no automatically induced poles unlike cage rotor, this deter the flux bonding between stator and rotor , As already loaded , this is a cumulative action there by machine stalls, Do let me know if you need further explanation.
What is the slipring used for in ac motors?
synchronous motors have a slipring to apply the dc field....Addition...to apply the excitation field to the armature/rotor that establishes the reaction with the rotating field in the stator, causing the rotor to turn the output shaft.Modern motors use a rotating transformer with stationary windings surrounding rotating windings mounted on the rotor shaft, thus eliminating the sliding contacts between the brushes and the sliprings. This improves efficiency and reliability.------- efficiency and reliability ??? ---------doing the transformer thing eliminates the need to check and change the brushes.you will still need to watch the bearings there are usually a couple brushes on the slip rings for redundancy (reliability?)There is no way possible the transformer arrangement will improve efficiencythe best tightly coupled transformers can be about 98% efficientsince this transformer must have a rather large gap so it may rotate it cannot be as closely coupled and will probably be more like 89% efficient.so at best the field with rotating transformer will be 10% less efficient than the slip rings.For a large plant the air compressors >300hp are always synchronous motorsby varying the field you can change the motor load from leading to lagging and as such save the VAR charges the power company generally tags on , easy to do with slip rings maybe not accessible with the package non slip ring motors.this of course requires monitoring the power at the service entrance and access to the exciter(s) on the large motor(s)alternators on cars have slip rings and many have a 2 wire external connection, which means the voltage is regulated on these 2 terminals, loose terminals longer wires perhaps a bad engine mount may mean the alternator will not charge the battery. without a kelvin connection there is no way the alternator can know what voltage the battery has. without a temperature sensor on the battery theres no way for the voltage to be related to the charge state. (less wire is cheaper in the short run but always less efficient)
