3-10 Preset Reference
Array [8]
Range:
Function:
0.00 %*
[-100.00 - 100.00 %]
Enter up to eight different preset references (0-7) in this parameter using array programming. The
preset reference is stated as a percentage of the value Ref
MAX
(par. 3-03 Maximum Reference) or
as a percentage of the other external references. If a Ref
MIN
different from 0 (Par. 3-02 Minimum
Reference) is programmed, the preset reference is calculated as a percentage of the full reference
range, i.e., on the basis of the difference between Ref
MAX
and Ref
MIN
. Afterwards, the value is added
to Ref
MIN
. When using preset references, select Preset ref. bit 0 / 1 / 2 [16], [17] or [18] for the
corresponding digital inputs in parameter group 5.1* Digital Inputs.
3-41 Ramp 1 Ramp-up Time
Range:
Function:
10.00 s*
[1.00 - 3600.00 s]
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 par. 4-18 during ramping. See
ramp-down time in par.3-42
Ramp 1 Ramp-down Time
.
par
.3
−
41 =
tacc
×
nnorm
par
.1
−
25
ref
rpm
s
See drawing above!
3-42 Ramp 1 Ramp-down Time
Range:
Function:
20.00 s*
[1.00 - 3600.00 s]
Enter the ramp-down time, i.e., the deceleration time from par.1-25
Motor Nominal Speed
to 0 RPM.
Choose a ramp-down time such that no overvoltage arises in the inverter due to regenerative op-
eration of the motor, and such that the generated current does not exceed the current limit set in
par. 4-18
Current Limit
. See ramp-up time in par.3-41
Ramp 1 Ramp-up Time
.
par
.3
−
42 =
tdec
×
nnorm
par
.1
−
25
ref
rpm
s
3-84 Initial Ramp Time
Range:
Function:
0 s*
[0–60 s]
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.
VLT
®
AQUA Drive
Instruction Manual
8 How to program the adjustable frequency
drive
MG.20.M5.22 - VLT
®
is a registered Danfoss trademark
8-17
8