Industrial Servo Motor YASKAWA 16-bit 50W AC SERVO MOTOR 3000RMP SGMAH-A5BAF41

 

 

 

 

 

 

 

 

 

 

 

 

The NEC allows standard fuses as overcurrent protection devices sized up to a maximum of 300% of the motor’s FLA to allow the motor to start.
• An exception allows the use of the next higher size fuse when the table value does not correspond to a standard size device.
C An additional exception allows the use of the next size larger device until an adequate size is found if the motor will not start without operating the device.
S Standard fuses will hold 500% of their current rating for approximately onefourth of a second.
C NOTE: Some special standard fuses will hold 500% of their current rating for up to two seconds.
• In order for a standard fuse to used as motor overload protection, the motor would have to start and reach its running speed in one-fourth of a second or less.
• Standard fuses will not generally provide any overload protection for hard starting installations because they must be sized well above 125% of a motor’s FLA to allow the motor to start.

 

 

 

 

The displacement angle is determined by the following relationship:
X = (Z ÷ 2π) × sin(Ta ÷ Th) where:
Z = rotor tooth pitch
Ta = Load torque
Th = Motors rated holding torque
X = Displacement angle.

Therefore if you have a problem with the step angle error of the loaded motor at rest you can improve this by changing the “stiffness” of the motor. This is done by increasing the holding torque of the motor. We can see this effect shown in the figure 5.
Increasing the holding torque for a constant load causes a shift in the lag angle from Q2 to Q1.
Step Angle Accuracy One reason why the stepper motor has achieved such popularity as a positioning
device is its accuracy and repeatability.
Typically stepper motors will have a step angle accuracy of 3 – 5% of one step. This error is also noncumulative from step to step. The accuracy of the stepper motor is mainly a function of the mechanical
precision of its parts and assembly. Figure 9 shows a typical plot of the positional accuracy of a stepper motor.

 

Step Position Error
The maximum positive or negative position error caused when the motor has rotated one step from the previous holding position.
Step position error = measured step  angle - theoretical angle

Positional Error
The motor is stepped N times from an initial position (N = 360°/step angle) and the angle from the initial position