Installation and Configuration
Ndrive HP 10/20/30 Manual
2-16
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2.5.3.3. Hall-Effect Phasing
For an AC brushless motor with an unknown hall sequence, one of two simple tests can
be performed on the motor to determine the proper connections to the Ndrive HP.
Be sure to first configure the axis parameters before
running the A3200\Programs\Samples\MsetDebug.Pgm.
See the “Getting Started” section in the Nview help for
configuration information.
The first of which, is by actively driving the motor under program control. The
A3200\Programs\Samples\MsetDebug.Pgm may be used for this purpose. The hall
signals must be swapped until they generate the sequence as defined in Figure 2-14.
After the Hall sequence is correct, the program can then correctly determine if a
commutation offset is required. The test program will indicate the required value of the
CfgMotOffsetAng axis parameter to correctly phase the motor.
The second method is a non-powered method, whereby the motor is disconnected from
the controller and connected in the test configuration as defined in Figure 2-14. This will
identify the hall signal (and motor) leads A, B and C. The equipment needed for the non-
powered test is a two-channel oscilloscope and three resistors (typically 10 K ohm, 1/2
watt) wired in a Wye configuration.
The tests outlined below do not require that the amplifier
be turned on since Figure 2-14 illustrates the generated
output voltage of the amplifier relative to the input Hall
sequences.
Before performing the test in Figure 2-14, ensure that the
motor leads are completely disconnected from the
amplifier.
Connect the ends of the three resistors to three motor leads. Use one channel of the
oscilloscope to monitor motor terminal A with respect to the Wye neutral (eg., the point
where all three resistors are connected together). Turn the shaft of the motor CW and
note the generated voltage. This voltage represents the phase A to neutral Counter EMF
(CEMF). With the second oscilloscope probe, determine the Hall switch that is in phase
with this voltage. Similarly, phase B and C should be aligned with the other two Hall
switches. This will identify each motor and hall lead, which are in-phase with each other.
Any motor and hall lead set may be phase A. The relative phasing between this set and
the other two sets will then determine which is phase B and phase C.
Refer to Figure 2-14 and note the generated output voltages of the amplifier relative to
the Hall sequences applied to Hall A, Hall B, and Hall C connections at connector J207.
For proper operation, the CEMF generated motor phase voltages should be aligned to the
amplifier’s output generated voltage with the given Hall effect sequence shown in Figure
2-14.
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