Danfoss VLT FCD 302 Operating Manual page 32

Operating Guide | VLT® Decentral Drive FCD 302
Figure 23: Parallel Connection of Motors
Problems can occur at start-up and at low RPM values when motor sizes differ widely. Motors of low-rated motor power have a relatively
high ohmic resistance in the stator. This high resistance calls for a higher voltage at start and at low RPM values.
To resolve the problem:
Reduce the load during start-up on the motor of lowest rated motor power.
l
Configure parallel connections only between motors of comparable rated motor power.
l
4.7 Mains and Drive Power Connections
4.7.1 Connecting AC Mains
Size the wiring based on the input current of the drive. For maximum wire sizes, see
l
Comply with local and national electrical codes for cable sizes.
l
4.7.2 Connecting the Drive to Mains
Table 6: Terminals 91, 92, and 93
Terminals
91 92
L1 L2
PE –
1. Connect the 3-phase AC input power wiring to terminals L1, L2, and L3.
2.
Depending on the configuration of the equipment, connect the input power to the mains input terminals or the input
disconnect.
3. Ground the cable in accordance with the grounding instructions, see
4. When supplied from an isolated mains source (IT mains or floating delta) or TT/TN-S mains with a grounded leg (grounded
delta), ensure that parameter 14–50 RFI Filter is set to [0] Off.
This setting prevents damage to the DC link and reduces ground capacity currents in accordance with IEC 61800-3.
32 | Danfoss A/S © 2025.04
Description
93 Mains voltage 3x380–480 V
L3
– Ground connection
7.1 Electrical Data.
4.4 Grounding, and 4.6.2 Grounding Shielded
AQ267036816112en-000301 / 130R0208
Electrical Installation
Cable.