Rockwell Automation 1336T Wiring and Grounding Guide, (PWM) AC Drives - Manual (Page 46)

46 Rockwell Automation Publication DRIVES-IN001M-EN-P - March 2014
Chapter 2 Power Distribution
Use PowerFlex Drives with
Regenerative Units
DC Bus Wiring Guidelines DC bus wiring refers to connecting the DC bus of an AC drive to the DC
connections on another piece of equipment. That equipment can include any or
all of these items:
• Additional AC drive
• Non-regenerative DC bus supply
• Regenerative DC bus supply
• Regenerative braking module
• Dynamic braking module
• Chopper module
For more information on the types of common DC bus configurations and
applications, refer to PowerFlex AC Drives in Common Bus Configurations,
publication
DRIVES-AT002 .
Drive Lineup
Generally, it is desirable for the drive lineup to match the machine layout.
However, if there is a mix of drive frame sizes used in the lineup, the general
system layout places the largest drives closest to the rectifier source. The rectifier
source does not need to be at the end of the system lineup. Many times it is
advantageous to put the rectifier in the middle of the lineup, minimizing the
distances to the farthest loads. This is needed to minimize the energy stored in
the parasitic inductance of the bus structure and thus lower peak bus voltages
during transient operation.
The system must be contained in one contiguous lineup. The bus cannot be
interrupted to go to another cabinet for the remainder of the system drives. A
contiguous lineup is needed to maintain low inductance.
ATTENTION: If a regenerative unit (for example, 1336 REGEN line regeneration
package) or other active front end (AFE) is used as a bus supply or brake,
disconnect the common mode capacitors as described in the user manual for
the drive. This guards against possible equipment damage.