The stator of the three-phase asynchronous motor and the synchronous machine, and the rotor of the three-phase wound motor have three-phase symmetrical windings. In the National Motor Standards, methods for measuring the DC resistance of these windings are specified. When measuring, the temperature of the winding to be tested must be measured. If the motor is in the actual cold state, the temperature can be corrected by the ambient temperature. When performing a type test or other test requiring accurate results, measure each phase resistance or each line resistance 3 times, and then take the average of 3 times as the measurement result.
● Direct measurement of phase resistance
When the stator or rotor three-phase winding phase of the motor has 6 terminals at the head and tail, or the three-phase winding is connected to the star (Y-shaped) inthe motor, but the neutral line is taken out except the three phase lines ( When the star point is also taken out, the DC resistance of each phase can be measured separately.
● Measuring line resistance
When the three-phase winding of the stator of the motor is connected to the star (Y) or the triangle (△) inside the motor, only the resistance of each of the two external ends (ie, the line resistance) can be measured, and then the corresponding phase resistance is converted by the formula.
JYR20S/10S transformer winding resistance tester, Yn/D(Y) three phase winding measurement.
The test items are required for 110kV/220kV substation acceptance and maintenance testing(with corresponding tester types):
|
Test Object |
Testing Item |
Tester Type |
|
|
Cable |
Cable AC Hipot Testing |
JYCX |
|
|
Cable Insulation Resistance Testing |
JYM KYORITSU |
||
|
Transformer |
Insulation Resistance of Winding |
JYM KYORITSU |
|
|
DC Leakage Testing in 1min |
JYDHV |
||
|
Winding Resistance Testing |
JYR50S |
||
|
Winding Deformation Testing |
JYP |
||
|
Turns Ratio Testing |
JYT-A |
||
|
AC Hipot Testing |
JYCX |
||
|
Short Circuit Impedance Testing |
JYW6300 |
||
|
Dan Delta Testing |
JYC |
||
|
Oil Breakdown Voltage (BDV)Testing |
JY6611 |
||
|
Oil Tan Delta Testing |
GTD-61A |
||
|
Switchgear |
Circuit Breaker/Disconnector Resistance |
JYL-200B |
|
|
Relay |
Relay Performance |
JY7003G |
|
|
On-load |
On-load Switchgear Testing |
JYK-I |
|
|
Tap Changer Dynamic Testing |
JYK-I |
||
|
Instrument Transformer |
Current Transformer (CT)Testing |
JYH-C |
|
|
Potential Transformer (PT)Testing |
JYH-C |
||
|
Surge Arrestor |
Zinc Oxide Characteristics Testing |
JY6800 |
|
|
1mA DC Reference Voltage |
JYDHV |
||
|
Capacitor |
Capacitor Current |
JY6700 |
|
|
Capacitor Inductance |
JY6700 |
||
|
Ground Grid |
Grounding Down Lead Earth |
JYD |
Related Articles:
What Test Items are Required for 110kV/220kV Substation Acceptance and Maintenance Testing?
What Tests Must be Done before the Transformer Leaves the Factory?
Main Factors Affecting the Operating Life of Transformers
What is the Purpose of Measuring the DC Resistance of the Transformer Winding?
Points to note in transformer oil breakdown voltage (BDV) test
DC winding resistance tester with 500 times tests on a single charge -JYR9310
