IEC 60034-4:2008 applies to three-phase synchronous machines of 1 kVA rating and larger with rated frequency of not greater than 500 Hz and not less than 10 Hz. The main changes with respect to the previous edition are as follows:
- removal of certain tests for lack of relevance in current practise;
- addition of provisions for tests on machines with brushless excitation;
- addition of a table of test methods indicating preferred tests and cross-references.