Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) Commissioning - ForGe Control - Manual (Page 77)

Rockwell Automation Publication 7000-IN012B-EN-P - June 2014 77
Commissioning the Drive Chapter 4
Analog Inputs
• Analog Command Input Scaling
– Prior to commencing the reference command input scaling it is
necessary to ensure that the reference command input selection has
been configured as desired. This requires setting Speed Reference Select
(P#7) to the appropriate input source (Torque Reference Select is
(P#401)).
– Set the utilized Reference Command minimum (SpdCmd Pot(L),
SpdCmd Anlg Inp(R) and SpdCmd DPI (D) to the desired value. The
minimum reference command input setting on a drive without an
encoder is 6 Hz. Without encoder control, do not set the reference
command minimum parameter below 6 Hz. A control with encoder
feedback will allow a minimum speed of 1 Hz. With encoder control,
do not set the reference command minimum parameter below 1 Hz.
– Set the utilized Reference command (L, R and D) Maximum
parameters so that with full reference command inputs, the associated
Reference command Variables read the desired maximum value.
– The various reference command maximums usually have to be increased
above the desired maximum value to compensate for the loading down
of their 10 volt input rails by the attached potentiometer or isolator.
Example: SpdCmd Anlg Inp (4-20mA) Reference command Input Scaling
The customer 4-20 mA speed input is coming to the Current Loop Receiver on
the ACB, and they want the maximum input to represent 60 Hz.
1. Set Reference Command Remote Maximum (Ref Cmd R Max) for 60 Hz.
2. Set the Reference Select parameter to ‘Remote 4-20 mA’.
3. Have the source supply 20 mA to the drive. Verify this with a multimeter
connected in series with the current source. Ensure that you are in Remote
mode with the selector switch, and look at the parameter Speed Command
In, which will represent that 20 mA signal.
4. Ensure that it reads 60 Hz. If it does not, increase the Ref Cmd R Max
value until this parameter reads 60 Hz.
Example: SpdCmd DPI (Digital) Reference command Input Scaling
The maximum value for a digital reference command is 32767; the minimum
value is 0. Values that are negative or out of bounds will result in the drive slowing
down to minimum speed.