44 L S94H201E_13426446_EN
Parameters
NOTE
If the phase current rating is not given, use this equation to obtain the nominal continuous
phase-to-phase winding current:
In = Continuous Stall Torque / Motor Torque Constant (Kt)
The same force x distance units must be used in the numerator and denominator in the equation above. If
torque (T) is expressed in units of pound-inches (lb-in), then Kt must be expressed in pound-inches per Amp
(lb-in/A). Likewise, if T is expressed in units of Newton-meters (N-m), then units for Kt must be expressed
in Newton-meters per Amp (N-m/A).
Example:
Suppose that the nominal continuous phase to phase winding current (In) is not given. Instead, we
look up and obtain the following:
Continuous stall torque T = 3.0 lb-in
Motor torque constant Kt = 0.69 lb-in/A
Dividing, we obtain:
In = 3.0 lb-in / 0.69 lb-in/A =4.35 (A)
Our entry for (In) would be 4.35.
Note that the torque (lb-in) units are cancelled in the equation above leaving just Amps (A). We would
have to use another conversion factor if the numerator and denominator had different force x distance
units.
Nominal Bus Voltage (Vbus)
The Nominal Bus Voltage can be calculated by multiplying the Nominal AC mains voltage supplied by 1.41.
When using a model with the suffix “S1N” where the mains are wired to the “Doubler” connection, the
Nominal Bus Voltage will be doubled.
Example:
If the mains voltage is 230VAC, Vbus = 230 x 1.41 = 325V
This value is the initial voltage for the drive and the correct voltage will be calculated dynamically
depending on the drive’s incoming voltage value.
Number of Poles
This is a positive integer number that represents the number of motor poles, normally 2, 4, 6 or 8.
Rotor Moment of Inertia (Jm)
From motor manufacturer or nameplate.
NOTE
Round the calculated result to 3 significant places.
5.2.5.2 For Incremental Encoder - Equipped Motors Only
Encoder Line Count
The encoders for servomotors normally have line counts of 1000, 1024, 2000, 2048, 4000, or 4096. The
Encoder Line Count is pre-quadrature and a positive integer.
Halls Order
Each hall signal is in phase with one of the three phase-phase voltages from the motor windings. Hall order
number defines which hall sensor matches which phase-phase voltage. Motor phases are usually called
R-S-T or U-V-W or A-B-C. Phase-Phase voltages are called Vrs, Vst, Vtr. Halls are usually called HALL-A,
HALL-B, HALL-C or just Halls 1, 2, 3. A motor’s phase diagram is supplied by motor vendor and usually
can be found in the motor data sheet or by making a request to the motor manufacturer. A sample phase
diagram is illustrated in Figure S912.
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