Mitsubishi Electric 800 Series Instruction Manual (Function page 496

17.12
Encoder feedback control
Magnetic flux Magnetic flux Magnetic flux
V/F V/F V/F
This controls the inverter output frequency so that the motor speed is constant to the load variation by detecting the motor
speed with the speed detector (encoder) to feed back to the inverter.
A Vector control compatible option is required.
Pr. Name
Overspeed detection
285
*1
A107
frequency
*2
359
Encoder rotation direction
C141
*2
367
Speed feedback range
G240
*2
368
Feedback gain
G241
*2
369
Number of encoder pulses
C140
*2
Encoder signal loss detection
376
enable/disable selection
C148
*1 The speed deviation excess detection frequency is used under Vector control or PM sensorless vector control. (Refer to
*2 The setting is available when a Vector control compatible option is installed.
 Setting before operation (Pr.359, Pr.369)
• Use Pr.359 Encoder rotation direction and Pr.369 Number of encoder pulses to set the rotation direction and the
number of pulses for the encoder.
NOTE
• Control with correct speed is not possible if the number of poles for the applied motor is incorrect. Check first before operation.
• Encoder feedback control is not possible when the rotation direction setting of the encoder is incorrect. (Operation of the
inverter is possible.)
Check the indicator on the parameter unit to confirm the direction.
 Selection of encoder feedback control (Pr.367)
• When a value other than "9999" is set in Pr.367 Speed feedback range, encoder feedback control is enabled. Set a target
value (frequency at which stable speed operation is performed) and specify the range around the value. Normally, use the
frequency converted from the slip amount (r/min) at the rated motor speed (rated load). If the setting is too large, response
becomes slow.
Driven load
Speed feedback range
Set value
(Set command)
Initial
Setting range
value
0 to 30 Hz
9999
9999
100
101
101
0 to 590 Hz
9999
9999
1 0 to 100
1024 2 to 4096
0
0
1
Regenerative load
Description
E.MB1 (Brake sequence fault) occurs when the difference
between the detection frequency and output frequency
exceeds the setting value under encoder feedback control.
Overspeed detection is disabled.
Set when using a motor (encoder) for which forward rotation is
clockwise (CW) viewed from the shaft.
Set when using a motor for which forward rotation (encoder) is
counterclockwise (CCW) viewed from the shaft.
Set the range of speed feedback control.
The encoder feedback control is disabled.
Set when the rotation is unstable or response is slow.
Set the number of encoder pulses.
Set the number of pulses before it is multiplied by 4.
Signal loss detection is disabled.
Signal loss detection is enabled.
17.12 Encoder feedback control
CW
CCW
page 137 for details.)
495
17. (G) Control Parameters
11
12
13
14
15
16
17
18
19
20