Mitsubishi Electric 800 Series Instruction Manual page 279

(F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
• The following table shows the actual deceleration time when stopping the inverter by selecting S-pattern acceleration/
deceleration D from operation to 0 Hz, as shown below, with the initial parameter settings.
Acceleration/
Pr.518
deceleration
reference
frequency
Pr.518/2
(Pr. 20)
Set deceleration time T1 = (set frequency - Pr.10 DC injection brake operation frequency)  Pr.8 / Pr.20
Actual deceleration time T2 = set deceleration time T1 + (Pr.518 + Pr.519) / 2
NOTE
• When acceleration/deceleration time (such as Pr.7 and Pr.8) is set to "0 s" under Real sensorless vector control and vector
control, linear acceleration and deceleration are performed for the S-pattern acceleration/deceleration A to D and backlash
measures (Pr.29 ="1 to 5").
• Set linear acceleration/deceleration (Pr.29 = "0 (initial value)") when torque control is performed under Real sensorless vector
control or vector control. When acceleration/deceleration patterns other than the linear acceleration/deceleration are
selected, the protective function of the inverter may be activated.
Variable-torque acceleration/deceleration (Pr.290 = "6")
• This function is suitable to accelerate/decelerate a variable torque load such as a fan and blower in a short time.
Linear acceleration/deceleration is performed in the area where the output frequency > base frequency.
[Variable-torque acceleration/deceleration]
Output frequency
Set frequency
Pr.3 Base frequency
Pr.7
Acceleration time
NOTE
• When the base frequency is out of the range 45 to 65 Hz, the linear acceleration/deceleration is performed even if Pr.29 = "6".
• Even if Pr.14 Load pattern selection = "1 (variable torque load)", variable torque acceleration/deceleration setting is
prioritized and the inverter operates as Pr.14 = "0 (constant torque load)".
• For the variable torque acceleration/deceleration time setting, set the time period to reach Pr.3 Base frequency. (Not the
time period to reach Pr.20 Acceleration/deceleration reference frequency.)
• The variable torque acceleration/deceleration is disabled during PM sensorless vector control. (Linear acceleration/
deceleration is performed.)
Parameters referred to ???????
Pr.3 Base frequency page 591
Pr.7 Acceleration time, Pr.8 Deceleration time, Pr.20 Acceleration/deceleration reference frequency
Pr.10 DC injection brake operation frequency
Pr.178 to Pr.182 (Input terminal function selection)
278
PARAMETERS
Linear deceleration
Pr. 8, Pr. 45, Pr. 111
Pr.519
Pr.519/2
DC injection
brake operation
frequency
T1
(Pr. 10)
T2
= (60 Hz - 3 Hz)  5 s / 60 Hz
4.75 s (actual deceleration time at linear deceleration)
= 4.75 s + (0.1 s + 0.1 s) / 2
= 4.85 s (deceleration time at S-pattern deceleration)
Pr.8
Deceleration time
page 599
page 415
Time
page 269