Danfoss VLT AutomationDrive FC 302 Design Manual page 24

Product Features
the application to a stop or losing control at any time.
Several variants of kinetic back-up can be selected.
Configure the behavior of the drive at mains drop-out in
parameter 14-10 Mains Failure and parameter 1-73 Flying
Start.
5.2.6 Automatic Restart
The drive can be programmed to restart the motor
automatically after a minor trip, such as momentary power
loss or fluctuation. This feature eliminates the need for
5 5
manual resetting, and enhances automated operation for
remotely controlled systems. The number of restart
attempts and the duration between attempts can be
limited.
5.2.7 Full Torque at Reduced Speed
The drive follows a variable V/Hz curve to provide full
motor torque even at reduced speeds. Full output torque
can coincide with the maximum designed operating speed
of the motor. This drive differs from variable torque drives
and constant torque drives. Variable torque drives provide
reduced motor torque at low speed. Constant torque
drives provide excess voltage, heat, and motor noise at less
than full speed.
5.2.8 Frequency Bypass
In some applications, the system can have operational
speeds that create a mechanical resonance. This
mechanical resonance can generate excessive noise and
possibly damage mechanical components in the system.
The drive has 4 programmable bypass-frequency
bandwidths. The bandwidths allow the motor to step over
speeds that induce system resonance.
5.2.9 Motor Preheat
To preheat a motor in a cold or damp environment, a small
amount of DC current can be trickled continuously into the
motor to protect it from condensation and cold starts. This
function can eliminate the need for a space heater.
5.2.10 Programmable Set-ups
The drive has 4 set-ups that can be independently
programmed. Using multi-setup, it is possible to switch
between independently programmed functions activated
by digital inputs or a serial command. Independent set-ups
are used, for example, to change references, or for day/
night or summer/winter operation, or to control multiple
motors. The LCP shows the active set-up.
22
VLT® AutomationDrive FC 302
Set-up data can be copied from drive to drive by
downloading the information from the removable LCP.
5.2.11 Smart Logic Control (SLC)
Smart logic control (SLC) is a sequence of user-defined
actions (see parameter 13-52 SL Controller Action [x])
executed by the SLC when the associated user-defined
event (see parameter 13-51 SL Controller Event [x]) is
evaluated as TRUE by the SLC.
The condition for an event can be a particular status, or
that the output from a logic rule or a comparator operand
becomes TRUE. The condition leads to an associated action
as shown in Illustration 5.3.
Par. 13-51
SL Controller Event
Par. 13-43
Logic Rule Operator 2
Par. 13-11
Comparator Operator
Illustration 5.3 SLC Event and Action
Events and actions are each numbered and linked in pairs
(states), which means that when event [0] is fulfilled
(attains the value TRUE), action [0] is executed. After the 1
action is executed, the conditions of the next event are
evaluated. If this event is evaluated as true, then the
corresponding action is executed. Only 1 event is
evaluated at any time. If an event is evaluated as false,
nothing happens in the SLC during the current scan
interval and no other events are evaluated. When the SLC
starts, it only evaluates event [0] during each scan interval.
Only when event [0] is evaluated as true, the SLC executes
action [0] and starts evaluating the next event. It is
possible to program 1–20 events and actions.
Danfoss A/S © 01/2018 All rights reserved.
Running
Warning
Torque limit
Digital input X 30/2
. . .
. . .
. . .
=
TRUE longer than..
. . .
. . .
Par. 13-52
SL Controller Action
Coast
Start timer
Set Do X low
Select set-up 2
. . .
st
MG38C202