NOTE
If
Freeze output
is active, the adjustable
frequency drive can only be stopped by
selecting
Motor coast
,
Quick stop,
or
DC
braking
via a digital input.
Speed up
and
Slow
are selected if digital control of the
up/down speed is required. This function is only active
if
Freeze reference
or
Freeze output frequency
has been
selected.
If
Speed up
is active, the reference or output frequency
will be increased; and if
Slow
is active, the reference
or output frequency will be reduced. The output fre-
quency is changed via the preset ramp times in pa-
rameters 209-210
Ramp 2
.
One pulse (logic '1' minimum high for 14 ms and a
minimum break time of 14 ms) will lead to a speed
change of 0.1% (reference) or 0.1 Hz (output frequen-
cy). Example:
Term
.29
Term.
33
Freeze ref/
freeze outp.
Function
0
0
1
No speed change
0
1
1
Speed up
1
0
1
Slow
1
1
1
Slow
Freeze reference
can be changed even if the adjustable
frequency drive has stopped. The reference will also
be saved if line power is disconnected.
Catch-up/Slow-down
is selected if the reference value
is to be increased or reduced by a programmable per-
centage value set in parameter 219
Catch-up/Slow-
down reference
.
Slow-down Catch-up
Function
0
0
Unchanged speed
0
1
Increase by % value
1
0
Reduce by % value
1
1
Reduce by % value
Ramp 2
is selected if a shift between ramp 1 (param-
eters 207-208) and ramp 2 (parameters 209-210) is
required. Logic '0' leads to ramp 1 and logic '1' leads
to ramp 2.
Preset reference, lsb
and
Preset reference, msb
makes
it possible to select one of the four preset references;
see the table below:
Preset ref.
msb
Preset ref.
lsb
Function
0
0
Preset ref. 1
0
1
Preset ref. 2
1
0
Preset ref. 3
1
1
Preset ref. 4
Preset reference on
is used for shifting between a re-
mote-controlled reference and a preset reference. It is
assumed that External/preset [2] has been selected in
parameter 214
Reference function
. Logic '0' means that
remote-controlled references are active, while logic '1'
means that one of the four preset references is active,
as can be seen from the table above.
Thermistor
is to be selected if a possibly integrated
thermistor in the motor is to be able to stop the adjust-
able frequency drive if the motor overheats. The cut-
out value is 3 k
Ω
.
If a motor features a Klixon thermal switch instead, this
can also be connected to the input. If motors operate
in parallel, the thermistors/thermal switches can be
connected in series (total resistance lower than 3 k
Ω
).
Parameter 128
Motor thermal protection
must be pro-
grammed for
Thermistor warning
[1] or
Thermistor trip
[2], and the thermistor is to be connected between a
digital input and terminal 50 (+10 V supply).
Precise stop, inverse
is selected to obtain a high degree
of accuracy when a stop command is repeated. A logic
0 means that the motor speed is ramped down to stop
via the selected ramp.
VLT
®
2800 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
MG.27.A2.22 - VLT
®
is a registered Danfoss trademark
61
Prog
rammi
ng