TI-3000JX Drive Test Utility for AMC Analog Drives

BACKGROUND

The Drive Test utility will help determine whether an AMC drive has a faulty phase or some other
problem by analyzing the behavior of the RED/GRN LED on the drive. This utility is included in TI-3000 V3.4 Beta13 and higher software revisions and in all TI-3000JX software revisions.

The LED on the drive is useful in determining whether a drive problem exists, but the LED
indication must be analyzed carefully to determine what it means. Basically a GRN LED means
the following:

1. The drive has been enabled.
2. The Hall effect inputs are not all HI or all LO.
3. The particular phase polarity energized at the time is working properly (providing that the
   speed pot is not set right on zero).

If any of the above items are not true, the LED will be RED. If it is RED, then some investigation
is required to determine which items or combination of items caused it to be RED.

These AMC drives use 6 step commutation. The drive has 3 phase outputs for the motor lines which are
energized one pair at a time with either positive or negative polarity. That amounts to 6 possible
ways to energize the lines. There are 6 valid Hall effect states, each of which corresponds to one
of the ways to energize the phase lines.

• If the pot is turned in the direction to run the motor in the
  forward direction (moving from 0 toward 1), the FWD polarities apply.
• If the pot is set to run in the reverse direction (moving from 0 toward 10), then the REV polarities apply.

The following table shows the 6 steps with corresponding Hall effect states and phase line voltages. The TI-3000JX display shows these patterns during the drive test.

For each phase, there is a power transistor available to apply positive voltage and one for
negative voltage to that phase. When the drive fails, it is often one of these 6 transistors that has
failed.  When the components in the drive fail, it could be risky connecting a motor to the drive because a high current might be applied to the windings depending upon the nature of the failure.

RUNNING THE TEST

Instructions for starting the test: 

1. Verify that the TI-3000JX and AMC drive are properly connected. 
2. Verify that nothing is connected to the drive's motor output leads.
3. Verify that the speed pot is set to 0.
4. From the Stop display, press the MENU key to access the Main Menu.
5. Use the Down Arrow key to move the cursor down to selection ‘2 Test Drive’.
6. Press the ENTER key to select the Drive Test Utility.
7. The screen will display the following warning:                                                       
8. After verifying that the drive armature leads are not connected to anything, press the
   RUN key to start the test. The LED on the drive should change from RED to GRN. Not changing to GRN could mean that the drive is not being enabled, or it could mean that the particular drive phase polarity selected has a problem. This should cause the following display to appear:                                                                                                                                The first column shows the step number which can be changed from 1 through 6.
   
   The second column shows the HI and LO states of the U, V, and W Hall signals currently applied to the drive from the TI-3000JX connector J10 pins 1, 2, and 3 respectively. You can verify these signals with a scope or voltmeter connected to each of these pins and referenced to J10 pin 7 or 8 (Ground).  If the voltage on pins 1, 2, and 3 do not agree with the display, then a TI-3000JX problem, drive problem, or cable problem are the most likely possibilities.
   
   The third column shows the voltage polarities the drive is applying to the U, V, and W
   armature leads when the speed pot is moved in the forward direction (from 0 toward 1)
   and in the reverse direction when the speed pot is moved in the reverse direction (from 0
   toward 9). The test always begins with this display on step 1.
    
9. Turn the speed pot from 0 to 1 (forward direction). This should apply the voltage polarity
   of +U –V, shown with the FWD heading. The LED should remain GRN. If it turns RED,
   there is likely a problem with this phase polarity on the drive. This kind of problems
   requires repair from the manufacturer, AMC.                                                                                  Note: It is difficult to measure these voltages. Any oscilloscope used must be isolated to
   prevent damage to the drive or scope and prevent danger to the user. Many meters will
   not read the PWM (pulse width modulation) used to generate these voltages, and the
   scope trace can be very confusing to interpret. Noting the color of the LED is the goal of
   these steps.
10. Press the Up Arrow key to move to step 2. Repeat the observations made for
    commutation step 1 in steps 8 and 9 of this test.
11. Continue with checking the drive with commutation steps 3 through 6 if no problems
    have been found. If problems have been found, then you may not wish to continue
    checking additional commutation steps.
12. Turn the speed pot back through 0 to 10 (reverse direction). Perform the checks that
    were done for the forward pot setting for commutation steps 1 though 6.
13. If the LED remained GRN thoughout the checkout, there is probably nothing wrong with
    the TI-3000JX, drive, and cabling. If you were having trouble running a motor, perhaps it
    was due to a mistake in the TI-3000JX setup. Make sure that you enter the correct Setup menu options for any motor being run using the "Generic" selections.
14. Press the MENU key to terminate the test. This should cause the drive LED to change
    from GRN to RED because the drive will be disabled.