Mitsubishi FR-A800

(G) Control parameters
626
PARAMETERS
5.16.14 Encoder feedback control
Setting before operation (Pr.144, Pr.359, Pr.369)
• When driving with V/F control and the encoder feedback control, set the number of motor poles in Pr.144 Speed setting
switchover in accordance with the applied motor. During Advanced magnetic flux vector, the Pr.81 Number of motor
poles setting is used, so the Pr.144 setting does not need to be changed.
• Using Pr.359 Encoder rotation direction and Pr.369 Number of encoder pulses, set the rotation direction and the
number of pulses for the encoder.
NOTE
• When the inverter is operated with Pr.144 = "0, 10, 110", it will cause E.1 to E.3.
• When set to Pr.144 = "102, 104, 106, 108", number with 100 subtracted will be set as the number of poles.
• When Pr.81 is set, setting value for Pr.144 will be automatically changed, but even if Pr.144 is changed, Pr.81 will not
automatically change.
• Control with correct speed is not possible if the number of poles for the applied motor is incorrect. Make sure to confirm
before operation.
• Encoder feedback control is not possible when the rotation direction setting of the encoder is incorrect. (Operation of the
inverter is possible.)
Confirm with the rotation direction indicator on the parameter unit.
By detecting the rotation speed of the motor with the speed detector (encoder) and feeding it back to the inverter,
output frequency of the inverter is controlled to keep the speed of the motor constant even for the load change.
Option FR-A8AP is required.
Pr. Name
Initial
value
Setting range Description
144
M002
Speed setting switchover
4
0, 2, 4, 6, 8, 10,
12, 102, 104,
106, 108, 110,
112
Set the number of motor poles for the operation by V/F
control and the encoder feed control.
285
H416
Overspeed detection
frequency

9999
0 to 30 Hz
When the difference between the detected frequency and
the output frequency exceeds the set value at the time of
encoder feedback control, an inverter fault (E.MB1) is
generated.
9999 Overspeed detection disabled.
359 
C141
Encoder rotation
direction
1
0
Set when using a motor for
which forward rotation
(encoder) is clockwise
(CW) viewed from the shaft
Set for the operation at
120 Hz or less.
100
Set for the operation at a
frequency higher than 120
Hz.
1
Set when using a motor for
which forward rotation
(encoder) is
counterclockwise (CCW)
viewed from the shaft
Set for the operation at
120 Hz or less.
101
Set for the operation at a
frequency higher than 120
Hz.
367 
G240
Speed feedback range
9999
0 to 590 Hz Set the range of speed feedback control.
9999 Disables encoder feedback control
368 
G241
Feedback gain
1 0 to 100 Set when the rotation is unstable or response is slow.
369 
C140
Number of encoder
pulses
1024 0 to 4096
Set the number of encoder pulses output.
Set the number of pulses before it is multiplied by 4.
 The speed deviation excess detection frequency is used when FR-A8AP (option) is mounted and vector control is performed. (For the details,
refer to page 206.)
 These parameters are available when FR-A8AP (option) is installed.
V/F
V/F
V/F
Magnetic flux
Magnetic flux
Magnetic flux
CW
CCW