35
Pn52B
Overload warning value
Speed
Position
Torque
Setting range
Setting Unit
Factory setting
Effective time
Category
0
〜
100
1%
20
Effective
immediately
Setup
5.11.2 Detection time of overload alarm (A.720)
When the heat dissipation of the servo motor is poor (the heat sink is small, etc.), the detection value of
overload alarm can be reduced to prevent overheating.
The coefficient for reducing the overload alarm detection value is Pn52C (motor overload detection base
current derating value).
Pn52C
Motor Overload Detection Base Current Decreases Ratings
Speed
Position
Torque
Setting range
Setting Unit
Factory setting
Effective time
Category
0
〜
100
1%
100
Power restart
Setup
Overload (continuous maximum) alarm (A.720) can be detected in advance to prevent overload of the motor.
(Note) The gray part of the above figure indicates the area where A.710 and A.720 occur.
5.12 Setting of Electronic Gear
"Command Unit" is the smallest unit of position data that moves the load. The command unit is to convert the
movement quantity into physical quantity units such as understandable distance (e.g. m and deg.), instead of
converting into pulses.
The electronic gear is a function of converting the movement amount specified according to the command unit
into the pulse number required for actual movement.
According to the electronic gear function, the workpiece movement amount per pulse of the input command
for servo drive is 1 command unit. That is, if servo-driven electronic gears are used, the pulses can be
converted into command units for reading.
(Note) When the upper device sets the electronic gear, the servo-driven electronic gear ratio is usually 1:1.
5.12.1 Setting of Electronic Gear Ratio
The electronic gear ratio is set by Pn20E and Pn210.
Important
The setting range of the electronic gear ratio is as follows.
0.001≤ Electronic Gear Ratio (B/A) ≤64000
A.040 (parameter setting exception alarm) will occur when the setting range is exceeded.
Pn20E
Electronic gear ratio (molecule)
Speed
Position
Torque
Setting range
Setting Unit
Factory setting
Effective time
Category
1
～
1073741824
1
1
Power restart
Setup
Pn210
Electronic gear ratio (denominator)
Speed
Position
Torque
Setting range
Setting Unit
Factory setting
Effective time
Category
1
～
1073741824
1
1
Power restart
Setup
Calculation Method for Setting Value of Electronic Gear Ratio
When the machine reduction ratio between the motor shaft and the load side is n/m (the load shaft rotates n
times when the motor rotates m times), the set value of the electronic gear ratio is obtained by the following
formula.
Overload detection time
Torque command [%]
Pn52C=50%
overload alarm
detection curve
Pn52C=100%
(factory set)
overload alarm
detection curve
