Wholesale coffee mechanical and electrical machine, by photoelectric sensor or magnetoelectric inductor speed signal into pulse signal. The measuring instrument will be the signal and the power frequency signal after processing, directly display the tested motor slip (or speed). A multi-turn coil with iron core is placed on the motor housing, and connected with the magnetoelectric galvanometer or cathodic oscilloscope. During the test, the time t required by stopwatch galvanometer or oscilloscope waveform full swing for N times is used, and the slip rate is calculated by the following formula: power supply frequency of the tested motor, in Hertz (Hz). Three, speed measuring instrument to measure the motor slip test, with the speed measuring instrument to measure the motor speed N2, and at the same time with a digital frequency meter to measure the motor power frequency F, slip s calculation formula.
The following is the synchronous speed corresponding to the actual power frequency of the tested motor, in r/min. Four, digital frequency meter to measure the motor slip using synchronous dynamometer load test, the digital frequency meter is connected to the dynamometer stator winding outlet end, to measure the frequency of the dynamometer, according to the formula converted into the test motor speed N1: frequency measured by the digital frequency meter; The polar logarithm of dynamometer. Measuring the slip rate of the motor On the end face of the motor shaft, draw a fan with the same number of poles as the motor, and use fluorescent lamp or neon lamp lighting. The power supply frequency of the flash lamp must be the same as that of the tested motor. During the test, stopwatch is used to measure the time t(S) required for N rotation of the fan plate, and slip St is calculated according to the following formula. In the motor test, slip is directly involved in the calculation of performance test and directly affects the calculation result of the test.
