Ac supply source considerations, Systems – Rockwell Automation 20Y PowerFlex Active Front End User Manual
Page 58
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Rockwell Automation Publication 20Y-UM001E-EN-P - July 2014
Chapter 2
AFE in IP21 Rittal Enclosure—Installation/Wiring
AC Supply Source
Considerations
The AFE Frame 10 or Frame 13 in a IP21 Rittal enclosure is suitable for use on a
circuit capable of delivering up to a maximum of 100,000 rms symmetrical
amperes, 600/690 volts with recommended fuses or circuit breakers.
The AFE must not be used on undersized or high-impedance supply systems.
The supply system kVA must be equal to or greater than the drive-related kW, and
the system impedance must be less than 10%. Operation outside these limits can
cause instability resulting in AFE shutdown.
System Impedance = (PowerFlex 700AFE kVA ÷ Transformer kVA) x Transformer % Impedance
You must take into account the kVA of all PowerFlex AFEs on the distribution
system and the system impedance of upstream transformers.
If a Residual Current Detector (RCD) is used as a system ground fault monitor,
use only Type B (adjustable) devices to avoid nuisance tripping.
Unbalanced, Ungrounded, or Resistive Grounded Distribution
Systems
If phase-to-ground voltage will exceed 125% of normal or the supply system is
ungrounded, see Wiring and Grounding Guidelines for Pulse Width Modulated
(PWM) AC Drives, publication DRIVES-IN001, for more information.
ATTENTION: To guard against personal injury and/or equipment damage caused
by improper fusing or circuit breaker selection, use only the recommended line
fuses or circuit breakers specified in
.
ATTENTION: The PowerFlex Active Front End has not been designed to be used
on IT (insulated tera) or corner-grounded power networks above 600V (phase-to-
phase voltage). Operation on such a network can cause a hazardous failure of the
insulation system of the AFE.
ATTENTION: The LCL Filter of the PowerFlex Active Front End contains common
mode capacitors that are referenced to ground. These devices must be
disconnected if the AFE is installed on a resistive grounded distribution system or
an ungrounded distribution system. See
for jumper locations.
ATTENTION: The power structure of the PowerFlex Active Front End in the IP21
Rittal enclosure contains common mode capacitors that must be
disconnected, regardless of the application in which the AFE is used. For
locations of the common mode capacitors and instructions to remove them, see
Frame 10 Power Structure on page 70