Danfoss VLT AQUA Drive FC 200 Instruction Manual page 111

6 How to Program the Low Harmonic Drive
3-41 Ramp 1 Ramp-up Time
Range:
Application [Application dependant]
dependent*
3-42 Ramp 1 Ramp-down Time
Range:
Application [Application dependant]
dependent*
6
3-84 Initial Ramp Time
Range:
0 s* [0–60 s]
3-85 Check Valve Ramp Time
Range:
0 s* [0–60 s]
6-18
Function:
Enter the ramp-up time, i.e., the acceleration time from 0 RPM to par. 1-25
Choose a ramp-up time such that the output current does not exceed the current limit in
Current Limit
par. 4-18 during ramping. See ramp-down time in par. 3-42
Time
.
tacc nnorm par
× .1 − 25
par
.3 − 41 =
ref rpm
Function:
Enter the ramp-down time, i.e., the deceleration time from par. 1-25
RPM. Choose a ramp-down time such that no overvoltage arises in the inverter due to regenerative
operation of the motor, and such that the generated current does not exceed the current limit set
Current Limit
in par. 4-18 . See ramp-up time in par. 3-41
tdec nnorm par
× .1 − 25
par
.3 − 42 =
ref rpm
Function:
Enter the initial ramp-up time from zero speed to Motor Speed Low Limit, par. 4-11 or 4-12. Sub-
mersible deep well pumps can be damaged by running below minimum speed. A fast ramp time
below minimum pump speed is recommended. This parameter may be applied as a fast ramp rate
from zero speed to Motor Speed Low Limit.
Function:
In order to protect ball check valves in a stop situation, the check valve ramp can be utilized as a
Motor Speed Low Limit [RPM]
slow ramp rate from par. 4-11
[Hz]
, to Check Valve Ramp End Speed, set by the user in par. 3-86 or par. 3-87. When par. 3-85 is
different from 0 seconds, the Check Valve Ramp Time is effectuated and will be used to ramp down
the speed from Motor Speed Low Limit to the Check Valve End Speed in par. 3-86 or par. 3-87.
®
MG.20.T1.22 - VLT is a registered Danfoss trademark
VLT AQUA Low Harmonic Drive Instruction
Motor Nominal Speed
Ramp 1 Ramp-down
s
Motor Nominal Speed
Ramp 1 Ramp-up Time
.
s
Motor Speed Low Limit
or par. 4-12
Manual
.
to 0