Rockwell Automation 23P PowerFlex DC Stand Alone Regulator and Gate Amplifier - Manual (Page 29)

Rockwell Automation Publication 23P-UM001D-EN-P - July 2012 29
Stand Alone Regulator Installation, Wiring and Configuration Chapter 2
amplifier (Op-Amp) circuit has been provided. For reference, the name of this
circuit will be called the “Binary Gain Amp,” because the gain of the amplifier is
set via binary DIP switches. See
Figure 12 on page 38 for a diagram of the Binary
Gain Amp circuit and Figure 13 on page 39 for DIP switch locations. When
properly configured, the output of the Binary Gain Amp is 0.612 Volts at 100%
load of the power module.
Note that the basis for scaling the current feedback is the power module, not the
motor. This is a different approach than legacy systems where the motor was used
as the basis for all of the current loop feedback scaling. This scaling works well as
long as the power module and the motor are closely matched. However, when
multiple power modules of the same size are used in the same process to run
different size motors, it may be desirable to enter lower values for parameter 465
[Drive Size] and scale the regulator rating from the motor full load amps. This
will reduce the size of the CT required and increase the resolution of the current
feedback signal.
Though the power module is used as the basis for the current feedback
calculation, the motor load must fall within the rating of the power module. If it
does not, the power module may trip on an overload or IOC when the motor is
running within its rating.
For example, if the regulator is configured so that the power module rating and
the motor rating are equal, and the “Heavy Duty” option is chosen for the motor,
the regulator will trip on a power module overload in 10 seconds when the system
is running at 200% current, instead of the 1 minute desired.
In the SAR configuration the power module rating will be entered by the user and
the regulator will use this value to determine overload and IOC trip points.
• Power Module Overload = 150% for 1 minute, or 200% for 10 seconds.
• Motor Overload - Standard Duty = 150% for 1 minute, (selection via
parameter 376 [MtrOvrld Type])
OR
• Motor Overload - Heavy Duty = 200% for 1 minute, (selection via
parameter 376 [MtrOvrld Type])
• Motor Full Load Amps entered in parameter 179 [Nom Mtr Arm Amps]