IS220PDIOH1A  keep the rated voltage and rated frequency running no-load until the mechanical loss is stable. Judgement of mechanical loss stability standard is: input power half an hour apart the difference between the two readings is not greater than 3% of the previous input power, in practice, generally empirical to determine the 1KW below the motor is generally running 15 ~ 30min, 1 ~ 10KW motor is generally running 30 ~ 60min, for motors larger than 10KW should be 60 ~ 90min. test. The voltage applied to the stator winding starts from 1.1 to 1.3Un, and gradually reduces to the lowest possible voltage value, so that the current starts to rise, during which 7 to 9 points are measured, and the following values should be measured at each point: three-phase voltage (such as three-phase balancing can be determined, only one phase can be measured), three-phase current, and input power P0.

IS220PDIOH1A accuracy of the electrical measuring instruments used shall be not less than 0.5 level, the accuracy of the three-phase wattmeter shall be not less than 1.0 level, the accuracy of the mutual transformer shall be not less than 0.2 level, the accuracy of the power transmitter shall be not less than 0.5% level (it shall be not less than 1% during the checking and testing), and the accuracy of the digital rotational speed measuring instrument and the accuracy of the rotational differential rate measuring instrument shall be not less than 0.1%±1 word, the accuracy of the torque measuring instrument shall be not less than 0.1%±1 word, and the accuracy of the torque measuring instrument shall be not less than 0.5%±1 word. 1 word, the accuracy of torque measuring instrument and dynamometer shall be not less than 1% (the measured efficiency shall be not less than 0.5%).