Technical information

1-66 Min. Current at Low Speed
Range: Function:
Size related* [ 1. - 200.
%]
Enter the minimum motor current at
low speed.
Increasing this current improves
developed motor torque at low speed.
Low speed is here defined as speeds
below 6% of the Nominal Speed of
Motor (1-25 Motor Nominal Speed) in
VVC
plus
PM Control
3.3.8 1-7* Start Adjustments
1-70 PM Start Mode
Option: Function:
[0] Rotor
Detection
Suitable for all applications where the motor
is known to be standing still when starting
(e.g. conveyors, pumps and non wind milling
fans).
[1] Parking If the motor turns at a slight speed (i.e. lower
than 2-5% of the nominal speed) e.g. due to
fans with light wind milling, select [1] Parking
and adjust 2-06 Parking Current and
2-07 Parking Time accordingly.
1-71 Start Delay
Range: Function:
0.0 s* [0.0 - 120.0 s]
The function selected in 1-80 Function at
Stop is active in the delay period.
Enter the time delay required before
commencing acceleration.
1-72 Start Function
Option: Function:
Select the start function during start delay.
This parameter is linked to 1-71 Start Delay.
[0] DC Hold/
Motor
Preheat
Energizes motor with a DC holding current
(2-00 DC Hold/Preheat Current) during the start
delay time.
[2] * Coast Releases shaft coasted converter during the
start delay time (inverter off).
Available selections depend on 1-10 Motor
Construction:
[0] Asynchron:
[2] coast
[0] DC-hold
[1] PM non salient:
[2] coast
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 1-73 Flying Start is enabled, 1-71 Start Delay
has no function.
Search direction for flying start is linked to the
setting in 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 2-02 DC Braking Time. Start will then
take place from 0Hz.
[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.
The parameter is always set to [1] Enable when
1-10 Motor Construction = [1] PM non salient.
Important related parameters:
•
1-58 Flystart Test Pulses Current
•
1-59 Flystart Test Pulses Frequency
•
1-70 PM Start Mode
•
2-06 Parking Current
•
2-07 Parking Time
•
2-03 DC Brake Cut In Speed [RPM]
•
2-04 DC Brake Cut In Speed [Hz]
•
2-06 Parking Current
•
2-07 Parking Time
The Flystart function used for PM motors is based on an
initial speed estimation. The speed will always be
estimated as the first thing after an active start signal is
given. Based on the setting of 1-70 PM Start Mode the
following will happen:
1-70 PM Start Mode = [0] Rotor Detection:
If the speed estimate comes out as greater than 0 Hz the
frequency converter will catch the motor at that speed and
resume normal operation. Otherwise, the frequency
converter will estimate the rotor position and start normal
operation from there.
1-70 PM Start Mode = [1] Parking:
If the speed estimate comes out lower than the setting in
1-59 Flystart Test Pulses Frequency then the Parking function
will be engaged (see 2-06 Parking Current and 2-07 Parking
Time). Otherwise the frequency converter will catch the
Parameter Description
VLT
®
HVAC Drive Programming Guide
44 MG11CD02 - VLT
®
is a registered Danfoss trademark
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