
B-65232EN/03 DESCRIPTIONS FOR FANUC AC SERVO MOTOR β series 4.SELECTING A MOTOR
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4.2 CHARACTERISTIC CURVE AND DATA SHEET
Performance of each motor model is represented by characteristic
curves and data sheet shown below.
4.2.1 Characteristic Curves
The typical characteristic curves consist of the following.
(1) Speed-torque characteristics
These are known as operating curves and describe the
relationship between the output torque and rotation speed of the
motor. The motor can be operated continuously at any
combination of speed and torque within the prescribed
continuous operating zone. To use the motor outside this zone,
obtain an operating condition from an overload duty curve, and
use the motor intermittently. The limit of continuous operating
zone is determined under the following conditions.
• The ambient temperature for the motor is 20°C.
• The drive current of the motor is pure sine wave.
The limit of the intermittent operating zone is determined by the
rated input voltage (200 V) applied to the drive unit. So, the limit
may change, depending on the voltage applied to the drive unit.
The torque in the continuous operating zone and intermittent
operating zone decreases by 0.19% with the β series or by 0.11%
with the βM series for each temperature increase of 1°C beyond
20°C due to the negative temperature coefficient of the magnet
material.
(2) Overload duty characteristic
This is known as a duty cycle curve and used to calculate the ON
time (during which the motor can be powered) and OFF time
(during which the motor must be kept at a rest to get cooled) for
the motor to run intermittently without becoming overheated.
This curve is determined by the limit of motor temperature.
However, the curve may also depend on the thermal protection
function of the drive unit and control unit.
See Section 4.2.3 for how to calculate the ON and OFF times.