Danfoss VLT AQUA Instruction Manual page 124

5 How to program the adjustable frequency
drive
3-84 Initial Ramp Time
Range:
0 s* [0–60 s]
5
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
5-18
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.
Function:
and the Check Valve no longer shall be active.
®
MG.20.P3.22 - VLT is a registered Danfoss trademark
VLT AQUA High Power Instruction Manual
Motor Speed Low Limit
or par. 4-12