Load And Motor - Fantech VLT 2800 Series Instruction Manual

Load and Motor

100 Configuration
(CONFIGURATION)
Value:
Speed control, open loop
(SPEED OPEN LOOP)
Speed control, closed loop
(SPEED CLOSED LOOP)
Process control, closed loop
(PROCESS CLOSED LOOP)
Function:
This parameter is used to select the configuration
to which the variable frequency drive 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 control, closed loop [3] is selected, the
internal process regulator is activated to enable precise
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 signal
must be added from the process and the process
regulator must be set in parameter group 400 Special
functions. Process closed loop is not active if a
DeviceNet card is mounted and Instance 20/70 or
21/71 is chosen in parameter 904 Instance types.
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.A8.22 - VLT is a registered Danfoss trademark
VLT® 2800 Series
101 Torque characteristic
(TORQUE CHARACT)
Value:
Constant torque
(CONSTANT TORQUE)
Variable torque low
(TORQUE: LOW)
[0]
Variable torque medium
(TORQUE: MED)
[1]
Variable torque high
(TORQUE: HIGH)
[3]
Variable torque low with CT start
(VT LOW CT START)
Variable torque medium with CT start
(VT MED CT START)
Variable torque high with CT start
(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 variable
frequency drive 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.
NOTE
Load and slip compensation are not active
if variable torque or special motor mode
have been selected.
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
39