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 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, make sure that the connection steps are low enough not to cause
voltage transients that would trip the drive.
3. Make sure 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 safety switch between the drive and the motor
ABB recommends to install a safety switch between the permanent magnet motor and the
drive output. The switch is needed to isolate the motor from the drive during maintenance
work on the drive.
Implementing an ATEX-certified motor thermal protection
With option +Q971, the drive provides ATEX-certified safe motor disconnection without
contactor using the drive Safe torque off function. To implement the thermal protection of
a motor in explosive atmosphere (Ex motor), you must also:
• use an ATEX-certified Ex motor
• order an ATEX-certified thermistor protection module for the drive (option +L357), or
acquire and install an ATEX-compliant protection relay
• do the necessary connections.
For more information, see:
Manual code (Eng-
lish)
User's manual
3AUA0000132231
ATEX-certified Safe disconnection function, Ex II (2) GD for ACS880 drives (+Q971)
application guide
3AXD50000027782
FPTC-02 ATEX-certified thermistor protection module, Ex II (2) GD (option +L537+Q971)
for ACS880 drives user's manual
Implementing the undervoltage control (Power-loss
ride-through)
See the firmware manual.
Guidelines for planning the electrical installation 89
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