Configuration of the frequency inverter

For work on the frequency inverter (FI):

Life-threatening voltages inside the FI housing!
danger

Life-threatening voltages inside the FI housing!

Contact can lead to serious injuries or death.

Never open the FI housing in operation!

Switch off the main switch and secure it against being switched on again.

Wait for at least 5 minutes until all capacitors have been discharged!

Before switching on again, close the FI housing.

In operation, the heat sink of the frequency inverter will get hot.
caution

In operation, the heat sink of the frequency inverter will get hot.

Risk of burns upon contact!

Prior to performing work on the frequency inverter, disconnect the power supply and wait for at least 15 minutes until the heat sink has cooled down.

Risk of frequency inverter failure caused by over-voltage!

Risk of frequency inverter failure caused by over-voltage!

Always disconnect the frequency inverter from the circuit to be tested before any high-voltage tests or an insulation test on lines in operation!

Risk of motor damage!

Risk of motor damage!

Check the switching frequency of the converter in the frequency inverter and set it, if necessary! Recommended value: 2 .. 6 kHz

With Bitzer Varipack frequency inverters, not all of these steps are necessary, since they are pre-configured and may be adapted to system requirements via the Best Software (see Operating instructions CB-100).

Vibrations

Danger of material fatigue and damage caused by vibrations in the system due to FI speed drive!

Danger of material fatigue and damage caused by vibrations in the system due to FI speed drive!

Check the whole system carefully at all possible operating frequencies for vibrations and resonances.

Blend out frequencies which cause resonances by appropriate parameter setting at the inverter!

If a vibration problem is identified at a certain speed or combination of speeds, it may be possible to modify or reinforce the piping design to correct it. After any such changes, the system should be retested across the entire speed range to make sure that solving the problem at one speed does not create a problem at another.

Alternatively, most inverters have the ability to program “gap” speed ranges (frequency bypass areas): While the compressor will be permitted to pass through the gap speed range, it will not be allowed to dwell within that range. Any frequency ranges where vibration or sound problems are identified can be “excluded” in this manner.

For further questions, please contact Bitzer.