This paper presents practical aspects related with the operation, compensation and protection of high power cycloconverters used in mining industry. Practical recommendations related with start-up, operation characteristics and un-expected shut-down process is described. Fuseless characteristics of modern cycloconverters are also discussed. Relevant current waveforms associated with the starting of a 20 MW synchronous motor SAG mill drive are presented, as well as current and voltage waveforms during a cycloconverter commutation failure.