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E-AC Drive Hardware Installation Guide Appendix A – Non-Compumotor Motors
USING NON-COMPUMOTOR MOTORS
We recommend that you use Compumotor motors with the E-AC Drive. If
you use a non-Compumotor motor, it must meet the following require-
ments:
•A minimum inductance of 2 mH, series or parallel, is required.
(Compumotor recommends a minimum inductance of 5 mH.)
•A minimum of 500VDC high-pot insulation rating from phase-to-phase and
phase-to-ground.
•The motor must be designed for use with a bipolar drive (no common center
tap).
•Motors with riveted rotors or stators are not recommended.
•Motors with solid rotors are not recommended.
•Test all motors carefully. Verify that the motor temperature in your applica-
tion is within the system limitations. The motor manufacturer’s maximum
allowable motor case temperature must not be exceeded. You should test the
motor over a 2-to-3 hour period. Motors tend to have a long thermal time
constant, but can still overheat, which results in motor damage.
CAUTION
Consult your motor vendor to verify that your motor meets the above specifications.
Consult your Automation Technology Center (ATC) if you have questions regarding the use
of a non-Compumotor motor with Compumotor equipment.
WIRING CONFIGURATIONS
Refer to the manufacturer’s motor specification document to determine
the motor’s wiring configuration. You can also determine the wiring
configuration with an ohmmeter using the procedures below (4-Lead
Motor, 6-Lead Motor, 8-Lead Motor). Once you determine the correct motor
wiring configuration, use the terminal connection diagram, shown at the
end of this section, that applies to your configuration.
4-LEAD MOTOR
1. Label one motor lead A+.
2. Connect one lead of an ohmmeter to the A+ lead and touch the other lead of
the ohmmeter to the three remaining motor leads until you find the lead
that creates continuity. Label this lead A–.
3. Label the two remaining leads B+ and B–. Verify that there is continuity
between the B+ and B– leads.
4. Proceed to the Terminal Connections section below.
6-LEAD MOTOR
1. Determine, with an ohmmeter, which three of the six motor leads are
common (one phase).
2. Label each one of these three motor leads A.
3. Using the ohmmeter, verify that the remaining three leads are common.
4. Label the remaining three leads B.
5. Set the ohmmeter range to the 100 ohm scale (approximately).
6. Connect the ohmmeter’s negative lead to one of the motor leads labeled A.
Alternately measure the resistance to the two remaining motor leads also
labeled A. The resistance measurements will reflect one of the following two
scenarios.
Scenario #1 — The resistance measurements to the two remaining motor
leads are virtually identical. Label the two remaining motor leads A+ and A–.
Label the motor lead connected to the negative lead of the ohmmeter
A CENTER TAP (this is the center tap lead for Phase A of the motor).