Mitsubishi Electric FR-A700 Instruction Manual page 386

Acceleration and deceleration
When S-pattern acceleration/deceleration D is set, acceleration/deceleration time will become
longer as follows:
Actual acceleration time T2 = set acceleration time T1 + (S-pattern time at a start of accelera-
tion+S-pattern time at a completion of acceleration) /2
Actual deceleration time T2 = set deceleration time T1 + (S-pattern time at a start of decelera-
tion+S-pattern time at a completion of deceleration) /2
Set acceleration/deceleration time T1 indicates Pr. 7, Pr. 8, Pr. 44, Pr. 45, Pr. 110 and Pr. 111.
Abb. 6-87: S-pattern time
b
CAUTION:
Even if the start signal is turned off during acceleration, the inverter will not decelerate
immediately to avoid sudden frequency change. (Likewise, the inverter will not
immediately accelerate when deceleration is changed to reacceleration by turning the
start signal on during deceleration, etc.)
Example The actual acceleration time when starting the inverter with an S-pattern acceleration/dece-
leration pattern D selected for a stop to 50Hz in the parameter initial setting is as shown
below (refer also to Fig. 6-87):
Set acceleration time T1 = (Pr. 20 − Pr. 13) × Pr. 7/Pr. 20
Actual acceleration time T2 = Set acceleration time T1 + (Pr. 516 + Pr. 517)/2
Set acceleration time T1
Actual acceleration time T2
6 - 206
Pr. 517
Pr. 516
Linear acceleration slope of
Pr. 516/2
Pr.7, Pr.44, Pr.110
T1
T2
= (50 Hz − 0,5 Hz) × 5 s/50 Hz
= 4,95 s (at linear acceleration))
= 4,95 s + (0,1 s + 0,1 s)/2
= 5,05 s (at S-pattern acceleration)
Deceleration reference frequency
(Pr.20)
Pr. 517/2
Starting frequency
(Pr. 13)
Parameter
I001554E