Rockwell Automation 20G PowerFlex SCR Bus Supply - Manual (Page 18)

1-4 Installation/Wiring
PowerFlex SCR Bus Supply User Manual
Publication 20S-UM001G-EN-P
AC Supply Source
Considerations The PowerFlex SCR Bus Supply is suitable for use on a circuit capable of
delivering a short circuit rating up to a maximum of 85,000 rms
symmetrical amperes.
If a Residual Current Detector (RCD) is used as a system ground fault
monitor, only Type B (adjustable) devices should be used to avoid nuisance
tripping.
Line Reactors
A minimum 3% rated three-phase AC line reactor must be installed for
minimum voltage drop unless the closest supply transformer is matched to
the kVA rating of the PowerFlex SCR Bus Supply. For recommended line
reactors, see
Line Reactors on page A-7 .
Install one three-phase AC line reactor for each SCR Bus Supply module. It
is recommended to maintain cable length symmetry between the
three-phase AC line reactors and the SCR Bus Supply connections. One
method is to mount the three-phase AC line reactors on the cabinet floor
under the SCR Bus Supply.
Important: It is recommended to keep all wired or bus bar connections
identical in size and length. This includes the AC line
connection to the three-phase AC line reactors and from the
three-phase AC line reactors to the SCR Bus Supply.
Unbalanced or Non-Solid Grounded Distribution Systems
Where the potential exists for abnormally high phase-to-ground voltages (in
excess of 125% of nominal), or the supply system is non-solid grounded,
refer to the Wiring and Grounding Guidelines for Pulse Width Modulated
(PWM) AC Drives (publication DRIVES-IN001).
!
ATTENTION: The PowerFlex SCR Bus Supply contains
protective MOVs that are referenced to ground. The MOVs should
be disconnected from ground if the SCR Bus Supply is installed on
any non-solid grounded power distribution system (IT-network).
For jumper location, see
Figure 1.7 on page 1-11 .