ABB ACS 600 Hardware Manual page 10

Safety Instructions
Power Factor
Compensation
Capacitors
Output Contactors
viii ACx = ACS/ACC/ACP
WARNING! The ACx 600 introduces electric motors, drive train
mechanisms and driven machines to an extended operating range. It
should be determined from the outset that all equipment is up to these
conditions.
WARNING! There are several automatic reset functions in the
ACS 600 (with Standard Application Program). If selected, they reset
the unit and resume operation after a fault. These functions should not
be selected if other equipment is not compatible with this kind of
operation, or dangerous situations can be caused by such action.
WARNING! If an external source for start command is selected and it is
ON, the ACS 600 (with Standard Application Program) will start
immediately after fault reset.
Power factor compensation capacitors and surge absorbers must not
be connected to the motor cables. These devices are not designed to
be used with frequency converters, and will degrade motor control
accuracy. They can cause permanent damage to the ACx 600 or
themselves due to the rapid changes in the ACx 600 output voltage.
If there are power factor compensation capacitors in parallel with the
ACx 600 make sure that the capacitors and the ACx 600 are not
charged simultaneously to avoid voltage surges which might damage
the unit.
If a contactor is used between the output of the ACx 600 and the motor
with DTC control mode selected, the output voltage of the ACx 600
must be controlled to zero before the contactor is opened: ACS 600
units via parameter 21.3 (ACP: 10.4), choose COAST. If RAMP is
selected, the output of the ACS/ACP 600 must be reduced to zero
using Parameter 16.1 by giving zero V DC to the selected digital input.
Otherwise the contactor will be damaged. In scalar control the
contactor can be opened with ACS/ACC/ACF 600 running.
Varistors or RC networks (AC) or diodes (DC) should be used to
protect against voltage transients generated by contactor coils. The
protective components should be mounted as close as possible to the
contactor coils. Protective components should not be installed at the
NIOC board terminal block.
ACS/ACC/ACP 604/607 Frequency Converters