Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control User Manual

Page 272

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Commissioning 4-67

7000 “C” Frame

7000L-UM300I-EN-P – Juen 2013

The analog outputs from the customer interface boards 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
milliamp 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 0.000pu. This is the minimum.

Adjust the Zero adjustment screw on the isolator to read 4 mA.

4. Set IDC Command Test to 1.500pu. 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 0.750pu to ensure you read 12 mA

(Half-scale). Set IDC Command Test to 0.000pu.

7. Assign the required parameter to the Analog Output port we have

calibrated.

8. Save all changes to NVRAM.

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