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 1Slow
1
1 1Slow
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.
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).
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
Programming
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