VLT
®
FCM Series
Programming
Description of choice:
Select
Disable
if this function is not required.
OK - same direction
: Chosen if the motor can
only rotate in same direction on cut-in.
OK - both directions
: Chosen if the motor can
rotate in both directions on cut-in.
DC-brake - before start
: Selected if the motor is
to be stopped using DC brake before the motor is
ramped up to the desired speed. The DC brake
time must be set in parameter 126.
Limitations:
1. Too low inertia will cause acceleration of the load,
which may be dangerous or prevent succesful
Flying start
. Use DC brake instead.
2. If load is driven eg. by "windmilling", the unit
might trip due to overvoltage.
3. Below 250 rpm the
Flying start
will not function.
446 Switching pattern
(SWITCH PATTERN)
Value:
60° AVM (60° AVM)
[0]
✭
SFAVM (SFAVM)
[1]
Function:
Description of choice:
Normally it is not necessary for the customer
to set this parameter.
461 Feedback conversion
(FEEDBACK CONV.)
Value:
✭
Linear (LINEAR)
[0]
Square root (SQUARE ROOT)
[1]
Function:
In this parameter, a function is selected which
converts a connected feedback signal from the
process to a feedback value that equals the square
root of the connected signal.
This is used, e.g. where regulation of a flow (volume)
is required on the basis of pressure as feedback signal
(flow = constant x
√
pressure). This conversion makes
it possible to set the reference in such a way that
there is a linear connection between the reference
and the flow required. See drawing.
Description of choice:
If
Linear
[0] is selected, the feedback signal and
the feedback value will be proportional.
If
Square root
[1] is selected, the frequency
converter translates the feedback signal to
be the square root value.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.03.H3.02 - VLT is a registered Danfoss trademark
67
