Danfoss VACON NX, Application Manual

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Similarly, if the speed of the auxiliary drives decreases slowly, a delay between the auxiliary drive stop and the frequency increase of
the variable speed drive can be programmed with parameter
ID 1026 .
If either of the values of parameters ID 1025 and ID 1026 is set to maximum (300.0 s), no frequency drop nor increase takes place.
f
out
t
Start freq. of aux drive + 1 Hz
Stop freq.
of aux drive - 1 Hz
Frequency drop
delay (par. ID1025)
Start delay of aux.
drive (par. ID1010)
Stop delay ofaux.
drive (par.ID1011)
Frequency
increase
delay
(par. ID1026)
Aux. drive
control
Aux. drive
speed
e
3
0
b
h
0
7
7
.1
0
Illustration 88: Frequency Drop and Increase Delays
10.431 (ID 1027) Autochange
Location in the menu: P2.9.24 (Pump and Fan Control Application)
Use this parameter to enable or disable the rotation of the start sequence and the priority of motors.
The automatic change of starting and stopping order is activated and applied to either the auxiliary drives only or the auxiliary
drives and the drive controlled by the AC drive depending on the setting of parameter
ID 1028 , Automatics selection. By default, the
Autochange is activated for 2 drives. See Illustration 20 and 10.631.2 Pump and Fan Automatics with Interlocks and Autochange .
10.432 (ID 1028) Autochange and Interlock Automatics Selection
Location in the menu: P2.9.25 (Pump and Fan Control Application)
Use this parameter to select whether the autochange is applied to the auxiliary drives or all drives.
Selection
number Selection name Description
0 Automatics (autochange/interlockings)
applied to auxiliary drives only The drive controlled by the AC drive remains the same. Only the mains
contactor is needed for each drive. See
Illustration 89 .
1 All drives included in the autochange/
interlockings sequence The drive controlled by the AC drive is included in the automatics and
two contactors are needed for each drive to connect it to the mains or
the AC drive. See
Illustration 90 .
AB296635287482en-000301 / DPD00903 | 275 Danfoss A/S © 2023.02
Parameter Descriptions
VACON® NX All-in-One
Application Guide