Mitsubishi Electric 800 Series Instruction Manual page 276

(F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
S-pattern acceleration/deceleration A (Pr.29 = "1")
• Use this when acceleration/deceleration is required for a short time until a high-speed area equal to or higher than the base
frequency, such as for the main shaft of the machine.
• The acceleration/deceleration pattern has the Pr.3 Base frequency (Pr.84 Rated motor frequency under PM sensorless
vector control) (fb) as the point of inflection in an S-pattern curve, and the acceleration/deceleration time can be set to be
suitable for the motor torque reduction in the constant-power operation range at the base frequency (fb) or more.
[S-pattern acceleration
/deceleration A]
fb
Time
• Acceleration/deceleration time calculation method when the set frequency is equal to or higher than the base frequency
Acceleration time t = (4/9)  (T/fb
Where T is the acceleration/deceleration time (s), f is the set frequency (Hz), and fb is the base frequency (rated motor
frequency)
• Reference (0 Hz to set frequency) of acceleration/deceleration time when Pr.3 = "60 Hz"
Acceleration/deceleration time
(s)
5
15
NOTE
• For the acceleration/deceleration time setting of the S-pattern acceleration/deceleration A, set the time to Pr.3 (Pr.84 under
PM sensorless vector control) instead of Pr.20 Acceleration/deceleration reference frequency.
S-pattern acceleration/deceleration B (Pr.29 = "2")
• This is useful for preventing collapsing stacks such as on a conveyor. S-pattern acceleration/deceleration B can reduce the
impact during acceleration/deceleration by accelerating/decelerating while maintaining an S-pattern from the present
frequency (f2) to the target frequency (f1).
[S-pattern acceleration
/deceleration B]
f1
f2
Time
NOTE
• When the RT or X9 signal turns ON during acceleration or deceleration with the S-pattern acceleration/deceleration B
enabled, a pattern of acceleration or deceleration changes to linear at the moment.
2 2
)  f + (5/9)  T
Set frequency (Hz)
60 120 200
5 12 27
15 35 82
400
102
305
PARAMETERS
5
GROUP
F
275