The requirement to equip systems to be more energy-efficient and free of noise emissions has never been as prevalent as is currently the case.
To comply with these demands Ziehl-Abegg developed the Fcontrol frequency inverter product range. These frequency inverters with integrated, all-pole sine filter, enable motors to be operated efficiently, with protection from any electromagnetic noise. In particular the operation of several motors in parallel with a frequency inverter is not a problem. It is not necessary to screen the motor cables when using the Fcontrol. The length of the cables is not restricted either. The sine-wave shape of the output voltage and output current means that the Fcontrol frequency inverter can also be designated as an “electronic transformer”.
Recognizing hazards
Constant improvements to the performance of electronic components have resulted in a major rise in the range of high-performance frequency inverters that are available on the market.
Frequency inverters have become less expensive and are gaining in popularity.
It is also important to know that standard frequency inverters without an all-pole sine filter, have a block-shaped or pulse-width modulated (PWM) output voltage. As specified in the European standard for rotating electrical machines, DIN IEC/TS 60034-17, motor bearings and windings which are exposed to this type of supply are also subject to correspondingly hazardous voltage peaks or ‘spikes’. Small motors such as those which are integrated into fans are at particular risk. The standard specifies the increasingly more demanding conditions placed upon motor winding systems induced by voltage peaks and the risk of bearing currents through capacitive coupled voltage, whereby premature motor bearing failure can be induced.
In the classic type of standard frequency inverter / drive motor combination, operating the system using short, screened power cables is generally not a problem. Normally, in this case, a motor is also used which has been designed for this type of operation.
To achieve safe and reliable parallel motor operation it is essential that the frequency inverter is equipped with an all-pole sine filter. This is why you should use the well-established Fcontrol product range for ensuring energy-efficient and quiet speed control to ensure that the motor windings and motor bearing are not subjected to any risk. Naturally, comprehensive control parameters for application fields in the refrigeration, air-conditioning and clean room technology have been stored in the controller and can be easily selected when starting up the unit. We will be only too glad to assist you in selecting the suitable Fcontrol for your particular application.
