Mitsubishi Electric FR-A800 Series Instruction Manual page 268

• The torque bias amount (Pr.847) and gain amount (Pr.848) when descending (reverse motor rotation when the Pr.840
setting is "1", forward motor rotation when the setting is "2") can be set in a range of 0 to 400%. When Pr.847 or
Pr.848 ="9999", the setting is the same for both descending and ascending (C16 to C19).
Pr.840
setting
(Forward motor rotation)
Torque command
terminal 1 gain
C18(Pr. 920)
1
Torque command
terminal 1 bias
C16(Pr. 919)
(Reverse motor rotation)
Torque command
terminal 1 bias
C16(Pr. 919)
2
Torque command
terminal 1 gain
C18(Pr. 920)
NOTE
• Input 0 to 10 V (torque command) to the terminal 1 that is used for the torque bias function. Any negative input voltage is
regarded as 0 V.
 Setting the torque bias amount automatically using terminal 1 (Pr.840 =
"3", Pr.846)
• The settings of C16 Terminal 1 bias command (torque/magnetic flux), C17 Terminal 1 bias (torque/magnetic flux),
C18 Terminal 1 gain command (torque/magnetic flux), C19 Terminal 1 gain (torque/magnetic flux) and Pr.846
Torque bias balance compensation can be set automatically according to the load.
• To set the torque bias amount with a voltage input to terminal 1, set Pr.868 Terminal 1 function assignment = "6".
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When ascending
Bias amount
C17(Pr. 919)
Terminal 1
input
Voltage for
max. load
Voltage for C19(Pr. 920)
balanced load
Pr. 846
Bias amount
Voltage for
balanced load
Pr. 846
Voltage for
max. load
C19(Pr. 920)
Terminal 1
input
C17(Pr. 919)
5.3 Speed control under Real sensorless vector control, vector control, PM sensorless vector control
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When descending
(Reverse motor rotation)
Bias amount
Fall-time
torque bias
terminal 1
bias
C17(Pr. 919)
Pr. 848
Voltage for
Fall-time
max. load
torque bias
Voltage for
C19(Pr. 920)
terminal 1
balanced load
gain
Pr. 846
Pr. 847
(Forward motor rotation)
Bias amount
Fall-time
Voltage for
torque bias
balanced load
terminal 1
Pr. 846 Voltage for
bias
max. load
Pr. 847
C19(Pr. 920)
Fall-time
torque bias
C17(Pr. 919)
terminal 1
gain
Pr. 848
Terminal 1
input
Terminal 1
input
5. PARAMETERS
1
2
3
4
5
6
7
8
9
10
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