F.A.Q.
Question about over voltage in an AC motor Drive.
Voltage in an AC Motor Drive centralizes on the branch line of the direct bus bar. In regular use, the average of Direct Current (D.C.) is three-phrase full-wave rectification in an AC Motor Drive. At 380V, the average of the D.C.: Ud =1.35U = 513V. In the process, the capacitors on the direct bus bar will be charged. The voltage up to 760V, the AC Motor Drive will adopt a certain protection. Therefore, every AC Motor Drive has a regular range at work. Voltage over the regular range may damage an AC Motor Drive. Over voltage in common as follows: 1. Over voltage in the input Alternating Current (A.C.) Voltage of the input A.C. surpasses regular range, you had better switch off the power supply and check. 2. Over voltage in generating electric power. This situation is most probability of occurrence. That is because the machinery is faster synchronous speed than actual speed, to make machinery still generate electric power and if an AC Motor Drive has no installed braking unit, the AC Motor Drive could get breakdown. (1) Pulling power of an AC Motor Drive is stronger than load . It means lower deceleration, faster input speed, to make the speed of machinery higher than frequency in an AC Motor Drive. Therefore, the voltage in direct current goes up and surpasses regular range, the AC Motor Drive could get breakdown. (2) While several machines pull the same load, breakdown could be happened then, because of no load distribution. Two machines pull the same load for example, when rotational speed in one of both machines is faster than the other machine, breakdown could be happened.