Running The Resistance Test - Allen-Bradley 1336 FORCE User Manual

Chapter 6
Troubleshooting
Running the Resistance
Test
6–26
The drive requires a motor resistance measurement to determine the
references for the regulators that control torque. The motor resistance
test measures the motor resistance and displays it in Rs Tune (parameter
236). The test runs for approximately 10 – 30 seconds.
When running this test, you should be aware of the following:
The motor should not rotate during this test although rated voltages
and currents are present and the possibility of rotation exists. For en-
coderless systems, you must visually verify that the motor does not
rotate.
This test is run at rated motor current and by–passes the normal cur-
rent limit functions.
Before running the resistance test make sure that you have entered the
correct motor nameplate information.
To run the motor resistance test:
1. Set bit 3 in Autotune/Diagnostic Selection (parameter 256).
2. Enable the drive.
The drive enable light turns off when the test is complete. When a
reading is obtained in RS Tune, perform the flux test.
Typical values for per unit motor resistance are in the range of 1% to 3%
as displayed in RS Tune. The value in RS Tune increases as the length of
wiring runs increase.