This standard specifies the rapid test evaluation method for the life of the stator winding insulation structure of low-voltage motors. This method uses the whole machine as a sample, achieves the purpose of rapid testing in a temperature step manner, and obtains a maximum likelihood estimator of the average life span of the insulation structure. This standard is applicable to three-phase and single-phase low-voltage motors operating under general conditions with various heat resistance levels. Their service life obeys logarithmic normal distribution. The tested insulation structure and the reference (baseline) insulation structure are compared in the same test. Make a relative assessment.
JB/T 7785-1995 history
2007JB/T 7785-2007 Evaluation method of insulation system's life by acceleration test for low-voltage electrical machines (Step stress method)
1995JB/T 7785-1995 Rapid test evaluation method for life of low-voltage motor insulation structure (step stress method)