Frequency inverter operation

Frequency inverters enable variable-speed operation. As a result, a fan-cooled motor (IC411)IEC 60034-6 Rotating electrical machines - Part 6: Classification of the cooling processes (IC code)) can be operated in speed ranges in which the specified temperature limits of the brake can no longer be adhered to during continuous duty. For this reason, thermal configuration of the brake must be carried out, see Thermal project planning BE.. brakes.

When using a forced cooling fan (IC416)IEC 60034-6 Rotating electrical machines - Part 6: Classification of the cooling processes (IC code), the cooling capacity is constant regardless of the motor speed. As a result, thermal project planning of the brake is not required for line operation.

Variable-speed drives are available for various control modes, e.g. V/f, VFC, VFC^PLUS, ELSM or CFC, which have different characteristics with regard to the control quality and the thermal load of the motor winding.

For the brake or temperature development of the brake, on the other hand, the control mode of the motor is of secondary importance and can therefore be neglected.