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1-71 Start Delay
Range:
Function:
0.0s
*
[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.
[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.
When par. 1-73 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 successful, a DC brake will
be activated in the time set in par. 2-02
Braking Time
. Start will then take place from 0 Hz.
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/Preheat
Energizes motor with a DC holding current (see par. 2-00).
1-81 Min Speed for Function at Stop [RPM]
Range:
Function:
3 RPM
*
[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:
0.0 Hz
*
[0.0 - 500 Hz]
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 and 4-12, Motor Speed Low Limit
, 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.
VLT
®
HVAC Drive Programming Guide
3. Parameter Description
MG.11.C5.02 - VLT
®
is a registered Danfoss trademark
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