Operating instructions

3.3.6 1-7* Start Adjustments
Parameters for setting special motor start features.
1-71 Start Delay
Range: Function:
0.0 s * [0.0 - 120.0
s]
The function selected in par. 1-80 Function at
Stop is active in the delay period.
Enter the time delay required before
commencing acceleration.
1-73 Flying Start
Option: Function:
This function makes it possible to catch a motor
which is spinning freely due to a mains drop-out.
When par. 1-73 Flying Start is enabled,
par. 1-71 Start Delay has no function.
Search direction for flying start is linked to the
setting in par. 4-10 Motor Speed Direction.
Clockwise [0]: Flying start search in clockwise
direction. If not successful, a DC brake is carried
out.
Both Directions [2]: The flying start will first make a
search in the direction determined by the last
reference (direction). If not finding the speed it will
make a search in the other direction. If not success-
ful, a DC brake will be activated in the time set in
par. 2-02 DC Braking Time. Start will then take place
from 0 Hz.
[0]
* Disabled Select Disable [0] if this function is not required
[1] Enabled Select Enable [1] to enable the frequency converter
to “catch” and control a spinning motor.
3.3.7 1-8* Stop Adjustments
Parameters for setting special stop features for the motor.
1-80 Function at Stop
Option: Function:
Select the frequency converter function after a
stop command or after the speed is ramped
down to the settings in par. 1-81 Min Speed for
Function at Stop [RPM].
[0]
* Coast Leaves motor in free mode.
[1] DC Hold/
Motor
Preheat
Energizes motor with a DC holding current
(see par. 2-00 DC Hold/Preheat Current).
1-81 Min Speed for Function at Stop [RPM]
Range: Function:
Application
dependent
*
[0 - 600 RPM] Set the speed at which to
activate par. 1-80 Function at
Stop.
1-82 Min Speed for Function at Stop [Hz]
Range: Function:
Application
dependent
*
[Application
dependant]
Set the output frequency at
which to activate
par. 1-80 Function at Stop.
3.3.8 Trip at Motor Speed Low Limit
In par. 4-11 Motor Speed Low Limit [RPM] and par. 4-12 Motor
Speed Low Limit [Hz] it is possible to set a minimum speed for
the motor in order to ensure proper oil distribution.
In some cases e.g. if operating in current limit because of a
defect in the compressor, the output motor speed can be
suppressed below Motor Speed Low Limit. To prevent damage
to the compressor it is possible to set trip limit. If the motor
speed drops below this limit, the frequency converter will trip
and issue an alarm (A49).
Reset will take place according to the selected function in
par. 14-20 Reset Mode.
If the trip must take place at a rather exact speed (RPM), it is
recommended to set par. 0-02 Motor Speed Unit for RPM and
use slip compensation, which can be set in par. 1-62 Slip
Compensation.
NOTE
To achieve the highest accuracy with the slip compensa-
tion, an Automatic Motor Adaptation (AMA) should be
performed. To be enabled in par. 1-29 Automatic Motor
Adaptation (AMA).
NOTE
Trip will not be active when using a normal stop- or
coast command.
1-86 Trip Speed Low [RPM]
Range: Function:
Application
dependent
*
[Application
dependant]
Set the desired motor speed for trip
limit. If the Trip Speed is set to 0, the
function is not active. If the speed at
any time after the start (or during a
stop) falls below the value in the
parameter, the drive will trip with an
alarm [A49] Speed Limit. Function at
stop.
0 RPM
* [Application
dependant]
Parameter Description
VLT
®
HVAC Drive Programming Guide
MG.11.CA.02 - VLT
®
is a registered Danfoss trademark 43
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