Danfoss VLT AQUA FC 202 Operating Instructions Manual page 93

How to programme the freque...
3-41 Ramp 1 Ramp Up Time
Range: Function:
Size [ 0.10 - Enter the ramp-up time, i.e. the
related 3600 s] acceleration time from 0 RPM to
*
parameter 1-25 Motor Nominal Speed.
Select a ramp-up time such that the
output current does not exceed the
current limit in 4-18 Current Limit during
ramping. See ramp-down time in
parameter 3-42 Ramp 1 Ramp Down Time.
t n par .1 − 25
×
acc nom
par .3 − 41 = s
ref rpm
3-42 Ramp 1 Ramp Down Time
Range: Function:
Size [ 0.10 - Enter the ramp-down time, i.e. the
related 3600 s] deceleration time from
*
parameter 1-25 Motor Nominal Speed to 0
RPM. Select 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 4-18 Current
Limit. See ramp-up time in
parameter 3-41 Ramp 1 Ramp Up Time.
t n par .1 − 25
×
dec nom
par .3 − 42 = s
ref rpm
3-84 Initial Ramp Time
Range: Function:
0 s [0 - Enter the initial ramp up time from zero speed to
*
60 s] Motor Speed Low Limit, parameter 4-11 Motor Speed
Low Limit [RPM] or 4-12 Motor Speed Low Limit [Hz].
Submersible 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. See
Illustration 5.13.
Speed
Motor Speed
High
Motor Speed
Low
Initial
Ramp
Illustration 5.13 Initial and Final Ramp Time
VLT AQUA Drive FC 202 Operation Instructions
Normal
Ramps
Final
Ramp
Time
MG20P402 - Rev. 2013-12-16
3-85 Check Valve Ramp Time
Range: Function:
0 s [0 - In order to protect ball check valves in a stop
*
60 s] situation, the check valve ramp can be utilized as a
slow ramp rate from parameter 4-11 Motor Speed
Low Limit [RPM] or 4-12 Motor Speed Low Limit [Hz],
to Check Valve Ramp End Speed, set by the user in
3-86 Check Valve Ramp End Speed [RPM] or
3-87 Check Valve Ramp End Speed [HZ]. When
3-85 Check Valve Ramp Time 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 3-86 Check Valve Ramp End Speed [RPM] or
3-87 Check Valve Ramp End Speed [HZ]. See
Illustration 5.14.
Speed
Motor Speed
High
Motor Speed
Low
Check valve
End Speed
Illustration 5.14 Check Valve Ramp
3-86 Check Valve Ramp End Speed [RPM]
Range: Function:
Size related [ 0 - par. Set the speed in [RPM] below Motor
*
4-11 RPM] Speed Low Limit where the Check
Valve is expected to be closed and
the Check Valve should no longer
be active.
Speed
Motor Speed
High
Motor Speed
Low
Check valve
End Speed
Illustration 5.15
5
Normal
Ramp
Time
Normal
Ramp
Time
91
5