Danfoss VT2800 Series User Manual

VLT
®
2800 Series
■ Load and Motor
■ Configuration
Selection of configuration and torque characteristics
has an effect on which pa rameters ca n be seen in the
display. If Open loop [0] is selected, all parameters
relating to PID regulat ion will be filtered out. This
means that the user only sees the parameters that
are relevant for a given application.
100 Configuration
(CONFIGURATION)
Value:
✭Speed control, open loop
(SPEED OPEN LOOP)
[0]
Speed control, closed loop
(SPEED CLOSED LOOP)
[1]
Process control, closed loop
(PROCESS CLOSED LOOP)
[3]
Function:
This parameter is used to select the configuration
to which the frequency converter is to be adapted.
This makes adaptation to a given application
simple, since the parameters not used in a given
configuration are hidden (not active).
Description of choice:
If Speed control, open loop [0] is selected, normal
speed control is obtained (without feedback
signal) with automatic load and slip compensation
to ensure a constant speed at varying loads.
Compensations are active, but may be disabled in
parameter 134 Load compensation and parameter
136 Slip compensation as required.
If Speed control, closed loop [1] is selected, better
speed accuracy is obtained. A feedback signal must
be added, and the PID regulator must be set in
parameter group 400 Special functions.
If Process con trol, closed loop [3] is selected, the
internal process regulator is activated to enabl
eprecise
control of a process in relation to a given process
signal. The process signal can be set to the relevant
process unit or as a percentage. A feedback sign
al
must be added from the process and the process
regulator must be set in parameter g roup 400 Special
functions. Process closed loop is not ac
tive if a
DeviceNet card is mounted and Instance 20/70 or
21/71 is chosen in parameter 904 Instance types.
101 Torque characteristic
(TORQUE CHARACT)
Value:
✭Constant torque
(CONSTANT TORQUE)
[1]
Variable torque low
(TORQUE: LOW)
[2]
Variable torque medium
(TORQU E: MED)
[3]
Variable torque high
(TORQU E: HIGH)
[4]
Variable torque low with CT start
(VT LOW CT START)
[5]
Variable torque medium w ith CT start
(VT MED CT START)
[6]
Variable torque high with CT start
(VTHIGHCTSTART)
[7]
Special motor m ode
(SPECIAL MOTOR MODE)
[8]
CT = Constant torque
Function:
This parameter enables a choice of principle
for adaptation of the U/f r atio of the fre quency
converter to the torque characteristic of the
load. See par. 135 U/f ratio.
Description of choice:
If Constant torque [1] is selected, a load-dependent U /f
characteristic is obtained, in which output voltage and
output frequency are increased at increasing loads in
order to main tain constant magn et i zation of the motor.
Select Variable torque low [2], Variable torque
medium [3] or Variable torque high [4], if the load
is square (centrifugal pumps, fans).
Variable torque - low with CT start [5], -mediumwith
CT start [6] or high with CT start [7], are selected if
you need a greater breakaway torque than can be
achieved with the three first characteristics.
NB!:
Load and slip compensation are not
active if variable torqu e or special motor
mode have been selected.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.E9.02 - VLT is a registered Danfoss trademark
68

Danfoss VT2800 Series Specifications

General

Brand	Danfoss
Model	VT2800 Series
Category	Controller
Language	English