3-57 Ramp 2 S-ramp Ratio at Decel. Start
Range:
Function:
50%
*
[1 - 99%]
Enter the proportion of the total ramp-down time (par. 3-52) where the deceleration torque increases The larger
the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the
application.
3-58 Ramp 2 S-ramp Ratio at Decel. End
Range:
Function:
50%
*
[1 - 99%]
Enter the proportion of the total ramp-down time (par. 3-52) where the deceleration torque decreases. The larger
the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the
application.
2.6.6. 3-6* Ramp 3
Configure ramp parameters, see 3-4*.
3-60 Ramp 3 Type
Option:
Function:
Select the ramp type, depending on requirements for acceleration and deceleration. A linear ramp will give
constant acceleration during ramping. An S-ramp will give non-linear acceleration, compensating for jerk in the
application.
[0]
*
Linear
[1]
S-ramp Const Jerk
Accelerates with lowest possible jerk.
[2]
S-ramp Const Time
S-ramp based on the values set in par. 3-61 and 3-62
NB!
If S-ramp [1] is selected and the reference during ramping is changed the ramp time may be prolonged in order to realize a jerk free
movement which may result in a longer start or stop time.
Additional adjustment of the S-ramp ratios or switching initiators may be necessary.
3-61 Ramp 3 Ramp up Time
Range:
Function:
Size related [0.01 - 3600.00 s]
Enter the ramp-up time, i.e. the acceleration time from 0 RPM to the rated motor speed n
M,N
(par. 1-25). Choose
a ramp-up time such that the output current does not exceed the current limit in par. 4-18 during ramping. The
value 0.00 corresponds to 0.01 sec. in speed mode. See ramp-down time in par. 3-62.
3-62 Ramp 3 Ramp down Time
Range:
Function:
Size related [0.01 - 3600.00 s ]
Enter the ramp-down time, i.e. the deceleration time from the rated motor speed nM,N (par. 1-25) to 0 RPM.
Choose a ramp-down time such that no over-voltage arises in the inverter due to regenerative operation of the
motor, and such that the generated current does not exceed the current limit set in par. 4-18. The value 0.00
corresponds to 0.01 s in speed mode. See ramp-up time in par. 3-61.
Par. 3
−
62 =
tdec s x nM, N (par. 1
−
25)
RPM
Δ
ref RPM
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Range:
Function:
50%
*
[1 - 99%]
Enter the proportion of the total ramp-up time (par. 3-61) in which the acceleration torque increases. The larger
the percentage value, the greater the jerk compensation achieved, and thus the lower the torque jerks in the
application.
FC 300 Programming Guide
2. How to Programme
MG.33.M3.02 - VLT
®
is a registered Danfoss trademark
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2
