Mitsubishi Electric FR-E700EX Instruction Manual page 129

Setting of acceleration/deceleration time and acceleration/deceleration pattern
(4) Faulty acceleration rate detection (Pr.375)
 When the acceleration rate of the motor rotation speed is increased, such as when the machine collides against a foreign
object, the drive unit can cause the acceleration rate error (E.OA) to trip. The rotation speed calculated inside the drive
unit is used as the motor rotation speed.
 Set Pr.375 Faulty acceleration rate detection level much larger than the acceleration/deceleration slope. If the setting of
Pr.375 Faulty acceleration rate detection level is lower than the acceleration/deceleration slope, the acceleration rate error
(E.OA) occurs even during normal operation.
 If rapid acceleration/deceleration is set for normal operation and the acceleration rate error (E.OA) occurs, the
acceleration rate error detection cannot be used. Set Pr.375 = "9999" to disable the acceleration rate error detection.
(5) Setting the acceleration/deceleration time in the low-speed range (Pr.791, Pr.792 )
 If torque is required in a low-speed range at 300 r/min or lower (600 r/min or lower for driving MM-GKR13), set Pr.791
Acceleration time in low-speed range and Pr.792 Deceleration time in low-speed range settings higher than the Pr.7 Acceleration
time and Pr.8 Deceleration time settings so that the mild acceleration/deceleration is performed only in the low-speed
range.
 If torque is required in the low-speed range (600r/min or less), set Pr.791 Acceleration time in low-speed range and Pr.792
Deceleration time in low-speed range settings higher than the Pr.7 Acceleration time and Pr.8 Deceleration time settings so that
the mild acceleration/deceleration is performed in the low-speed range.
 Set the time for the acceleration from a stop to Pr.20 Acceleration/deceleration reference speed as the acceleration time. Set
the time for the deceleration from Pr.20 Acceleration/deceleration reference speed to a stop as the deceleration time.
Acceleration time
in low-speed range
Slope set by Pr.791
REMARKS
 The RT signal acts as the second function selection signal and makes the other second function valid. (Refer to page 141) )
 If the Pr.20 setting is changed, the Pr.125 and Pr.126 (speed setting signal gain speed) settings do not change. Set Pr.125 and Pr.126
to adjust the gains.
 Set Pr.791 higher than Pr.7, and Pr.792 higher than Pr.8. If set as Pr.791 < Pr.7, the operation is performed as Pr.791 = Pr.7. If set
as Pr.792 < Pr.8, the operation is performed as Pr.792 = Pr.8.
 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.
Rotation speed
(r/min)
Rotation speed
0
Acceleration rate
(r/min/ms)
0
Fault output
Acceleration time
Slope set by Pr.7
Speed command
Pr.375
Time
E.OA
Pr.375
Time
E.OA
E.OA
Low-speed range
Time
Deceleration time
in low-speed range
Deceleration time
Slope set by Pr.792
Slope set by Pr.8
4
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