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"Phasing out" is a method to either check the phase shift across a transformer due to the winding characteristics or phasing to another transformer to ensure that the transformer is connected the same way. These tests usually apply to three phase Grid Transformers.
Grid transformers can be wound in a number of ways. The simplist version is described as YY0. That is two Y wound three phase winding laid directly against each other. There is no phase shift ie 0 degrees. Other transformers can be wound YD that is a Y winding wound against a delta winding. Automaticallly there will be a phase shift across this winding.
Field test involve energising the high voltage side with a 3 phase supply. Voltages are then measured across windings. Ie measure the input voltage on Primary side Eg 230 Volts then measure the volts on secondary side between each phase to fill up a test table.
eg Rp Rs, Rp Ys, Rp Bs etc....
From these measurements it is possible by drawing a suitable vector diagram of each phase to show the phasing of each phase, the ratio and the angle of the transformation across the transformer.
An alternative (simpler) method is to use an oscilliscope from this superimpose the to voltages and measure the angle between them. It isn't so effective in the field with large voltages and not quite as accurate.
Lastly to phase the new transformer with the existing network measure the voltages of each phase to the corresponding phase on the network. The reading should be zero if youre phasing is correct and to confirm full phase voltage between phases.
Wiki User
∙ 12y ago
Wiki User
∙ 11y agoIn new installations, when installing three phase motors, it is a 50 - 50 chance that the motor will turn the correct rotation. There is an instrument that can reduce these odds to 100% correct each time. The three leads are connected to the three motor connections. The motor is hand rotated in the direction that it is supposed to turn when connected. The readout tells you how the connection is to connected to the supply system to to make the motor turn correctly when connected.
See related links below.
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How to Test for single phasing?
You can do that in one of three ways: 1- current on each phase, 2- phase to gnd voltage, 3- phase to phase voltage, preferably with multiple meters, the three lines has to be balanced within ~ 3%
Need of load test of squirrel cage induction motor?
usually you just need to read the name plate only the manufacturer needs to test to come up with numbers on the nameplate most common load for testing motors is a water brake dynamometer
Kelvins double bridge experiment?
this is just for induction test
What will happened if one phase loss in three phase motor?
The motor will hum and act like it is trying to run it's commonly known as single phasing, it will also heat up quite rapidly and if you set up your circuit correctly and have the proper thermal overload protection on it it will trip and protect the circuit and the motor. If the problem is in the motor winding you will have to rewind the motor or replace it
What is a no load test on three phase induction motor?
if a motor blows fuses and it didnt before disconnect the coupling try to turn the machine and the motor by hand first with the coupling disconnected see if the motor runs ok chances are the trouble is in the machine the motor can have bad bearings very basic troubleshooting
Theory for brake test on three phase induction motor?
why three phase induction motor is delta connected
Load test on 3 phase induction motor?
When you do a load test on a 3-phase induction motor you are checking the power factor, viz slip, and efficiency of the motor. You can test various loads with this test.
What has the author R P Chen written?
R. P. Chen has written: 'Linear induction motor research vehicle wheel/rail adhesion test' -- subject(s): Car-wheels, Electric motors, Induction, Induction Electric motors, Testing
How to Test for single phasing?
You can do that in one of three ways: 1- current on each phase, 2- phase to gnd voltage, 3- phase to phase voltage, preferably with multiple meters, the three lines has to be balanced within ~ 3%
Which size of motor requires a solo run test?
All motors should be test bumped to check for rotation. Larger three phase motors should be disconnected from the load before this is done.
Need of load test of squirrel cage induction motor?
usually you just need to read the name plate only the manufacturer needs to test to come up with numbers on the nameplate most common load for testing motors is a water brake dynamometer
What are No Load And Locked Rotor tests on a three phase induction motor?
Doing a No Load test of a 3-phase induction motor involves the measuring of current, voltage, torque etc with no load on the rotor shaft, meaning that it is free to turn but is not driving anything else. Similarly a Locked Rotor test involves the measuring of current, voltage, torque etc with the rotor shaft "locked" i.e. prevented from turning, which is the worst loading condition the motor would ever have to contend with.
How do you zero phase current tranformer test?
How do you zero phase current transformer test
Kelvins double bridge experiment?
this is just for induction test
What is Kelvins double bridge experiment?
this is just for induction test
What is polarity test and continuity test?
a test to be conduct for find the phase...
What are No Load And Blocked Rotor tests on a three phase induction motor?
There is no such thing as a "Blocked" Rotor test so that must be a misunderstanding of the correct description, which is "Locked" Rotor test.For more information see the answer to the Related Question shown below.
