scope:

This technical specification applies to machines complying with IEC 60349-2. The total losses of a converter-fed motor may be determined by summation of the component losses derived from no-load and load tests. The total input power is the sum of the power at the fundamental frequency and at all other frequencies. In all practical cases the latter input includes the losses resulting from the voltage and current harmonics in the converter supply by using suitable instrumentation it can be derived from measurement of the total and fundamental frequency power inputs when the machine is on load. The losses supplied at the fundamental frequency cannot be measured directly and so are derived from measurement of the fundamental frequency load current and the fundamental frequency no-load power input.