Provide cheap AC power motor, ac is to consider the power factor, P=UIcos, this is single-phase AC.For a three-phase balanced circuit, multiply by the square root of 3. U and I are the effective values of line voltage and line current.
What is the reason why the voltage and current coils of the phase meter are in good condition but not moving?I think there are many reasons: 1. There are faults in the electricity meter itself, such as broken voltage coil, such as blocked rotation of the disk.2. There are problems with the connection method of the electricity meter, such as the two current terminals are short connected, such as the terminals of the voltage coil are in bad contact or not connected, which does not affect the power consumption, but the meter does not run.3. The load is pure inductance or pure capacitance, since the power factor is zero, the meter will not run.4. Circuit without power or voltage too low, or no load, or load too small, less than the sensitivity of the meter, such as less than 1% of the rated current.
Theoretically, if measures are taken to make the ac current flowing through the two sets of windings of a single-phase motor have a certain phase difference, it can be started.How to make a certain phase difference between two magnetic potentials or magnetic flux that have been staggered at a certain Angle in space is the starting point to solve the starting problem.According to this, the single-phase AC asynchronous motor can be divided into two categories: phase type and hood type.
