It could be assumed that properly planned, dimensioned, designed, installed, operated and maintained motor systems and drives should not break down. In reality however, these conditions are hardly ever ideal. Statistics show that an annual downtime of 0.5-4% is to be expected, of which 30% of the motor breakdowns can be attributed to motor overloads. Insulation damage accounts for 20% of all breakdowns while phase failure, bearing damage and ageing account for 14%, 13 % and 10% respectively. Breakdowns in motor operations result in tremendous losses both in time and money.