Danfoss VLT AQUA Operating Instructions Manual page 97

VLT AQUA Low Harmonic Drive Operating In-
structions
3-41 Ramp 1 Ramp Up Time
Range:
Application [Application dependant]
dependent*
3-42 Ramp 1 Ramp Down Time
Range:
Application [Application dependant]
dependent*
3-84 Initial Ramp Time
Range:
0 s* [0 – 60 s]
3-85 Check Valve Ramp Time
Range:
0 s* [0 – 60 s]
3-86 Check Valve Ramp End Speed [RPM]
Range:
0 [RPM]* [0 – Motor Speed Low Limit [RPM]] Set the speed in [RPM] below Motor Speed Low Limit where the Check Valve is expected to be closed
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 during ramping. See ramp-down time in par. 3-42 Ramp 1 Ramp Down
par. 4-18
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
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
Current Limit . See ramp-up time in par. 3-41 Ramp 1 Ramp Up Time .
in par. 4-18
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] or par. 4-12 Motor Speed Low Limit
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.
Function:
and the Check Valve no longer shall be active.
®
MG.20.T1.02 - VLT is a registered Danfoss trademark
6 How to Programme the Low Harmonic Drive
s
Motor Nominal Speed to 0 RPM.
s
Motor Nominal Speed .
6
97