Danfoss FC322 Series Instruction Manual page 89

Automation VT Drive FC322
Instruction Manual
3-84 Initial Ramp Time
Range:
0 s* [0 – 60 s]
3-85 Check Valve Ramp Time
Range:
0 s* [0 – 60 s]
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
slow ramp rate from par. 4-11 Motor Speed Low Limit [RPM]
[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.U1.22
8 How to Programme the Frequency Converter
or par. 4-12
8
Motor Speed Low Limit
89