Load And Motor - Danfoss VLT FCD 311 Design Manual

Load and Motor

Configuration
Selection of configuration and torque characteristics
has an effect on which parameters can be seen in
the display. If Open loop [0] is selected, all parame-
ters relating to PID regulation will be filtered out.
This means that the user only sees the parameters
that are relevant for a given application.
100 Configuration
100
(CONFIGURATION)
Value:
Speed regulation, open loop
(SPEED OPEN LOOP)
Speed regulation, closed loop
(SPEED CLOSED LOOP)
Process regulation, closed loop
(PROCESS CLOSED LOOP)
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 configura-
tion are hidden (not active).
Description of choice:
If Speed regulation, open loop [0] is selected, nor-
mal speed control is obtained (without feedback
signal) with automatic load and slip compensation to
ensure a constant speed at varying loads. Compen-
sations are active, but may be disabled in parameter
134 Load compensation and parameter 136 Slip
compensation as required.
If Speed regulation, closed loop [1] is selected, bet-
ter 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 regulation, closed loop [3] is selected, the
internal process regulator is activated to enable pre-
cise regulation 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 feed-
back signal must be added from the process and the
= factory setting. () = display text [] = value for use in communication via serial communication port
56
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VLT FCD Series
process regulator must be set in parameter group
400 Special functions.
101 Torque characteristic
101
(TORQUE CHARACT)
Value:
Constant torque
(CONST ANT TORQUE)
Variable torque low
(TORQUE: LOW)
Variable torque medium
(TORQUE: MED)
Variable torque high
(TORQUE: HIGH)
Variable torque low with CT start
[0]
(VT LOW CT START)
Variable torque medium with CT start
[1]
(VT MED CT START)
Variable torque high with CT start
[3]
(VT HIGH CT START)
Special motor mode
(SPECIAL MOTOR MODE)
CT = Constant torque
Function:
This parameter enables a choice of principle for
adaptation of the U/f ratio of the frequency 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 maintain constant magnetization 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], - medium with
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 torque or special motor mode have
been selected.
MG.04.A1.02 - VLT is a registered Danfoss trade mark
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