Control Block Diagram; Acceleration Time Setting (Pr.7, Pr.20); Deceleration Time Setting (Pr.8, Pr.20) - Mitsubishi Electric FR-F800 Instruction Manual

(F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
Control block diagram
JOG
(Pr.16)
Output frequency Pr.147
(or Pr.147= "9999" )
Acceleration and
deceleration time
(Pr.7, Pr.8)
Output frequency Pr.147
Second acceleration and
deceleration time
(Pr.44, Pr.45)
Acceleration and
deceleration time
in low-speed range
(Pr.791, Pr.792)
Acceleration time setting (Pr.7, Pr.20)
• Use Pr.7 Acceleration time to set the acceleration time required to reach Pr.20 Acceleration/deceleration reference
frequency from stop status.
• Set the acceleration time according to the following formula.
Acceleration time setting = Pr.20  Acceleration time from stop status to maximum frequency / (maximum frequency -
Pr.13)
• For example, the following calculation is performed to find the setting value for Pr.7 when increasing the output
frequency to the maximum frequency of 50 Hz in 10 s with Pr.20 = "60 Hz (initial value)" and Pr.13 = "0.5 Hz".
Pr.7 = 60 Hz  10 s / (50 Hz - 0.5 Hz)
12.1 s
Pr.20
(60Hz/50Hz)
Deceleration
Acceleration Pr.7
time Pr.44 time
Deceleration time setting (Pr.8, Pr.20)
• Use Pr.8 Deceleration time to set the deceleration time required to reach a stop status from to Pr.20 Acceleration/
deceleration reference frequency.
• Set the deceleration time according to the following formula.
Deceleration time setting = Pr.20  deceleration time from maximum frequency to stop / (maximum frequency - Pr.10)
• For example, the following calculation is used to find the setting value for Pr.8 when increasing the output frequency to the
maximum frequency of 50 Hz in 10 s with Pr.20 = 120 Hz and Pr.10 = 3 Hz.
Pr.8 = 120 Hz  10 s / (50 Hz - 3 Hz)
25.5 s
NOTE
• If the acceleration/deceleration time is set, the actual motor acceleration/deceleration time cannot be made shorter than the
shortest acceleration/deceleration time determined by the mechanical system J (moment of inertia) and motor torque.
• If the Pr.20 setting is changed, the Pr.125 and Pr.126 (frequency setting signal gain frequency) settings do not change. Set
Pr.125 and Pr.126 to adjust the gains.
• Under PM motor control, if the protective function (E.OLT) is activated due to insufficient torque in the low-speed range, set
longer acceleration/deceleration times only in the low-speed range in Pr.791 Acceleration time in low-speed range and
Pr.792 Deceleration time in low-speed range.
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PARAMETERS
RT-OFF
RT-ON
Running
frequency
Time
Pr.8
Pr.45
Output frequency 10% of the rated motor frequency
JOG-ON
JOG-OFF
Output frequency 10% of the rated motor frequency
Acceleration time
or
deceleration time