The detection and judgment method of the good and bad of the motor
How to test the AC three-phase motor good or bad
1, Shaking table shaking, 500V shaking table can be, shaking the three terminals on the line to the motor shell insulation resistance, should be above 0.5M ohms on the description of no short circuit to ground.
2, Multimeter test: measure the resistance value between the three phases of A/B/C, whether equal, should be about the same, too much difference can also turn, but not for long, remember that the larger the motor, the smaller the resistance value! But not three phases are 0 Europe, unless you are particularly large, such as more than 50KW motor! Remember that if the speed control motor resistance value of the six terminals is not the same yo!
3, Check the bearings, fan, general wrap motor let all change! Because sometimes the bearing clamping will also burn the motor yo!
4, The no-load current of the motor is generally 10% to 50% of the rated current, sometimes the motor idle current is also zero, yo!
5, The motor rated current operation, is fully loaded operation, the output power is basically 100%. Running current is small, indicating that the motor output power becomes smaller, is light load operation.
How to detect the good and bad of AC single-phase motor
Use 500V megohm meter to measure the insulation resistance of motor winding and shell, should not be less than 0.5 megohm; use multimeter to measure each lead of winding, no broken wire; the above are in line with the requirements, the motor is good.
It is convenient to detect the goodness of capacitor with pointer multimeter (there is also a digital meter with capacitance file, which can be measured directly).
Dial the multimeter to 1K or 10K resistance file, test the 2 leads of the capacitor, the meter needle quickly to the right deflection after slowly back to the left side of the capacitor is good; always deflected to the right side of the capacitor is broken; pointer does not move the capacitor internal disconnection or no capacity. This method can only determine the good or bad of the capacitor.
The good and bad of DC motor
First look at whether there is a broken line, test the resistance is normal.
If it is a brush DC motor, you can let the rotor rotate, use a multimeter to measure the output DC power is normal.
If it is a brushless DC motor, and three-phase lead, you can let the rotor rotate, with a multimeter to measure the output voltage is normal.
The output voltage is proportional to the speed.