Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive - Air-Cooled (A Frame) - Manual (Page 208)

4-54 Commissioning
7000A-RM001A-EN-P – January 2011 7000 “A” Frame
System Test (cont.)
Highlight the appropriate Analog Scale
parameter and press Enter. You can enter
your new value, and then press Enter, and
EXIT (F10). Ensure you save to NVRAM
when you are finished.
The analog outputs from the ACB to IFM are stated as 0 to 10 volts,
but in actual fact their outputs are typically 0.025 to 9.8 or 9.9 V. This
is due to the rails being loaded down by an attached speed
potentiometer or signal conditioner impedance. Incorporated signal
conditioners usually have 0 to 10-volt inputs and 4 to 20 mA outputs.
An additional error is incorporated in the signal conditioners, so if they
are calibrated for 0 to 10 volts input, there will not be exactly 4 to 20
mA out.
It is now necessary to calibrate the external 4 to 20 mA signal
conditioners.
1.
Set a digital multimeter to mA and place it in line with the signal
conditioners. If the output of the conditioner is terminated, the
meter can be used as a load.
2. Assign a parameter to the Analog Output port that we wish to
calibrate. This parameter should be one that we can change from
minimum to maximum for test purposes only. IDC Command
Test is a good example. See previous page on assigning an output.
3. Set IDC Command Test to 0.000 pu. This is the minimum.
Adjust the Zero adjustment screw on the isolator to read 4 mA.
4. Set IDC Command Test to 1.500 pu. This is the maximum.
Adjust the Span adjustment screw on the isolator to read 20 mA.
5. Repeat the process until no more adjustments are required.
6. Set IDC Command Test to 0.750 pu to ensure you read 12 mA
(Half-scale). Set IDC Command Test to 0.000 pu.
7. Assign the required parameter to the Analog Output port we have
calibrated.
8. Save all changes to NVRAM.