Planning the electrical installation 65
Implementing the Power-loss ride-through function
The Power-loss ride-through function is activated when parameter 47.02 Undervolt ctrl is
set to Enable (default in Standard pump control program).
Note: If the drive is equipped with a line contactor, it opens in a power loss and must be
closed again by a time relay.
Using power factor compensation capacitors with the
drive
Power factor compensation is not needed with AC drives. However, if a drive is to be
connected in a system with compensation capacitors installed, note the following
restrictions.
WARNING! Do not connect power factor compensation capacitors or harmonic
filters to the motor cables (between the drive and the motor). They are not meant
to be used with AC drives and can cause permanent damage to the drive or
themselves.
If there are power factor compensation capacitors in parallel with the three phase input of
the drive:
1. Do not connect a high-power capacitor to the power line while the drive is connected.
The connection will cause voltage transients that may trip or even damage the drive.
2. If capacitor load is increased/decreased step by step when the AC drive is connected
to the power line, ensure that the connection steps are low enough not to cause
voltage transients that would trip the drive.
3. Check that the power factor compensation unit is suitable for use in systems with AC
drives ie, harmonic generating loads. In such systems, the compensation unit should
typically be equipped with a blocking reactor or harmonic filter.
Using a contactor between the drive and the motor
Arrange the control of the output contactor by applying one of the alternatives described
below.
Alternative 1:
When you have selected to use the default motor control mode (DTC) and
motor coast stop in the drive, open the contactor as follows:
1. Give a stop command to the drive.
2. Open the contactor.
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