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What is the possible cause if three phase motor has imbalanced current on winding?
Wiki User
∙ 10y ago
It sounds like there may be a partial short in one the the three motor windings. What should be done it to megger the motor. This will tell you if all three winding are not shorting to each other and not shorting or partial shorting to ground. If the reading is over 2 megohms to infinity then the motor is all right. Below .5 megohms (500000 ohms) the motor should be cautiously used and will probably have to go in for a rewind.
If the burning is in the motors junction box then the burning could be caused by loose conections between the feeder wires and the motor winding leads.
Wiki User
∙ 10y ago
Wiki User
∙ 12y agoThe reason of buning winding of three phese motor is runing for with out loud and rang conection
Wiki User
∙ 11y agoIf more than one winding is burnt open the motor will not operate.
Wiki User
∙ 10y agoIf the three currents are unequal it's a sign of a fault in the motor. The nature of the fault depends on the currents.
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What cause ice formation on suction lines of the compressor?
The system and the load have become imbalanced. It will need to be looked at as the possible causes are many.
What are field windings and armature windings in a dc motor and generator?
generators have two types of winding , * at armature also called armature winding( winding around shaft , we can say), which is the moving part. note that armature also consists of magnets along with windings. hence produces field arount it. * and at stator also called field winding, because when armature rotates its flux(field) is cutted by the stator windings and produces mutually induced e.m.f in it( in stator windings off course) causing current to flow. this current also produces some electric field around it which is in return cutted by the armature windings hince a little amount of e.m.f ( also called back e.m.f) produced in armature due to stator winding current. know this current in armature (due to back e.m.f produced by stator winding) produces additional field , hence causing more current in stator winding. this is the reason that why stator windings are called field winding( as they cause electric field of armature stronger and cause more current in output). note that out put is taken from the stator windings in generators.
What cause earth fault in a motor?
The Rotor Protection relay is used in synchronous motors and generators to identify the presence of an earth fault in the rotor winding. While the winding in the rotor is insulated from the ground during normal operation, the Rotor is subjected to stresses due to vibration, heat, etc. These stresses can cause the winding to give way in a particular place and the winding can get earthed. While a single earthing in the winding is not immediately damaging. It sets the stage for damage if a second failure should occur. The second earthing can cause a short-circuit through the rotor causing extensive damage to the rotor and the winding. The currents produced during a rotor earth fault can cause excessive vibration and disturb the magnetic balance inside the alternator. These forces can cause the rotor shaft to become eccentric and in extreme cases cause bearing failure. Hence, it is necessary that any earthing in the rotor is detected at the earliest. In slip ring rotors, carbon deposits on the slip rings may compromise the insulation resistance of the rotor. Hence, the slip rings need to be inspected for any deposits. The Rotor Earth Fault Protection Device consists of a current injection device which applies an AC voltage to the rotor winding by means of a slip ring fitted on the rotor. The current is applied to the rotor through a coupling capacitor. In the normal condition, the system is floating and the current flowing through the device is zero as the resistance is high. When a fault occurs, the current increases causing the relay to operate. The relay can be configured for alarm or trip depending on the criticality.
HOW TO CALCULATE THE IMPEDANCE FOR THE TRANSFORMER?
The term, 'percentage impedance', is a little misleading, as it is defined as 'the value of primary voltage that will cause rated current to flow in the secondary winding, expressed as a percentage of the rated primary voltage'. So, the test is carried out as follows: the secondary winding is short-circuited through an ammeter capable of reading the rated secondary current. A variable voltage is applied to the primary winding. The primary voltage is gradually increased until the ammeter indicates rated secondary current. That primary voltage is then expressed as a percentage of the rated primary voltage -and that value is the transformer's 'percentage impedance'.
How insulation resistance of a motor winding checked If the insulation resistance is low What is likely to cause?
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What cause ice formation on suction lines of the compressor?
The system and the load have become imbalanced. It will need to be looked at as the possible causes are many.
How does toxins harm a fetus?
they are passed to the fetus and cause imbalanced compounds that effect DNA
What are field windings and armature windings in a dc motor and generator?
generators have two types of winding , * at armature also called armature winding( winding around shaft , we can say), which is the moving part. note that armature also consists of magnets along with windings. hence produces field arount it. * and at stator also called field winding, because when armature rotates its flux(field) is cutted by the stator windings and produces mutually induced e.m.f in it( in stator windings off course) causing current to flow. this current also produces some electric field around it which is in return cutted by the armature windings hince a little amount of e.m.f ( also called back e.m.f) produced in armature due to stator winding current. know this current in armature (due to back e.m.f produced by stator winding) produces additional field , hence causing more current in stator winding. this is the reason that why stator windings are called field winding( as they cause electric field of armature stronger and cause more current in output). note that out put is taken from the stator windings in generators.
What would cause the ignition coil to burn out on the 1989 corvette?
If you mean prematurely burn out, there are several things. A faulty control module or even a bad plug or wire will cause the coil to produce maximum voltage or produce voltage too often. A coil is exactly that. A winding or coil of wire energized producing voltage which is then stepped up to a higher voltage winding with a step up transformer. The more often you send current through a winding, which will cause heat, the sooner it will eventually burn out.
What cause earth fault in a motor?
The Rotor Protection relay is used in synchronous motors and generators to identify the presence of an earth fault in the rotor winding. While the winding in the rotor is insulated from the ground during normal operation, the Rotor is subjected to stresses due to vibration, heat, etc. These stresses can cause the winding to give way in a particular place and the winding can get earthed. While a single earthing in the winding is not immediately damaging. It sets the stage for damage if a second failure should occur. The second earthing can cause a short-circuit through the rotor causing extensive damage to the rotor and the winding. The currents produced during a rotor earth fault can cause excessive vibration and disturb the magnetic balance inside the alternator. These forces can cause the rotor shaft to become eccentric and in extreme cases cause bearing failure. Hence, it is necessary that any earthing in the rotor is detected at the earliest. In slip ring rotors, carbon deposits on the slip rings may compromise the insulation resistance of the rotor. Hence, the slip rings need to be inspected for any deposits. The Rotor Earth Fault Protection Device consists of a current injection device which applies an AC voltage to the rotor winding by means of a slip ring fitted on the rotor. The current is applied to the rotor through a coupling capacitor. In the normal condition, the system is floating and the current flowing through the device is zero as the resistance is high. When a fault occurs, the current increases causing the relay to operate. The relay can be configured for alarm or trip depending on the criticality.
What causes a person to become unbalanced?
A build up of fluid in the ears can cause a person's equilibrium to become imbalanced.
What might cause a winding sound on a 1997 Villager?
wind
Why should current transformers be shorted off load?
If a current transformer (CT) has its secondary winding left open-circuit whilst there is current in the primary winding, the magnetic core will saturate, large eddy currents will occur in the core causing the core to heat up rapidly, the voltage in the secondary will rise to dangerously high values and the current transformer will fail catastrophically. To further describe why this happens, consider an "ideal" transformer (which has no losses at all - a reasonable assumption because transformers are generally very efficient), therefore, power in equals power out. Power can be calculated by multiplying the voltage by the current (amps using the symbol I) in each case. Therefore: Pin = Pout, or Vin x Iin = Vout x Iout, or again Vprim x Iprim = Vsec x Isec (where prim refers to the primary or input winding and sec refers to the secondary or output winding). The primary winding of current transformer is connected in series with the load, therefore the current in the primary winding is fixed by the load. Thus if the secondary winding is open circuit, the secondary current is zero, and the voltage will rise to a very high value in trying to balance this equation. It will exceed the breakdown value of the insulation and will cause an arc because the insulation will never withstand an infinite voltage! In addition to this if the secondary is open circuit, there is no magnetic flux from secondary winding current, to balance and negate any of the magnetic flux from the primary winding current as occurs in power and voltage transformers. This is the reason for magnetic saturation of the core, and the rapid heating effect of the current transformer which affects the ability of the insulation to withstand the high voltage described above. The failure of current transformers under these conditions can be explosive and highly dangerous.
What happens when secondary of the transformer is open?
The secondary winding leakage inductance limits the current during a short. It seems that the current through the primary is limited by winding resistance and leakage resistance when the secondary is shorted.
Why would direct current be unsiutable for transformers?
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors-the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core, and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF) or "voltage" in the secondary winding. This effect is called mutual induction.Transformers depend on the changing of magnetic fields within the transformer. Direct current would cause a magnetic field to form in the primary coil, but its the change that induces the current in the secondary field. the change only occurs if an alternating current is applied.
What makes the armature in the electric motor rotate?
from Faraday's law of electromagnetic induction : when a current carrying conductor cuts the magnetic field an E.M.F (electro motive force) is produced and it sets up in such a direction so as to oppose the cause of it. the stator winding of a motor which produces the R.M.F (rotating magnetic field) serves as the magnetic field and the armature winding is the current carrying conductor which cuts the magnetic field , thus an EMF is induced in the armature which again produces a force to oppose the emf produced in the armature winding.
Can spinning metal cause voltage?
Yes, if its magnetized and in the presence of an electrical winding.
