Danfoss VLT FC 100 Series Programming Manual page 50

Parameter Description
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 Hld/ Energizes motor with a DC holding current
Motr (2-00 DC Hold/Preheat Current) during the start
Preheat delay time.
[2] Coast Releases shaft coasted drive 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
that is spinning freely due to a line 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 unable to find the speed, it
will 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 Adjustable
frequency drive 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:
®
VLT HVAC Drive Programming Guide
1-73 Flying Start
Option:
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
adjustable frequency drive will catch the motor at that
speed and resume normal operation. Otherwise, the
adjustable frequency drive 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 DC Brake Current and
2-07 DC Braking Time). Otherwise, the adjustable frequency
drive will catch the motor at that speed and resume
normal operation. Please refer to description of 1-70 PM
Start Mode for recommended settings.
Current limitations of the Flystart Principle used for PM
motors:
MG11CD22 - VLT ® is a registered Danfoss trademark
Function:
•
1-58 Flystart Test Pulses Current
•
1-59 Flystart Test Pulses Frequency
•
1-70 PM Start Mode
•
2-06 DC Brake Current
•
2-07 DC Braking Time
•
2-03 DC Brake Cut-in Speed [RPM]
•
2-04 DC Brake Cut-in Speed [Hz]
•
2-06 DC Brake Current
•
2-07 DC Braking Time
•
The speed range is up to 100% Nominal Speed or
the field weakening speed (which ever is lowest).
•
PMSM with high back EMF (>300VLL (rms)) and
high winding inductance(>10mH) needed more
time for reducing short circuit current to zero and
may be susceptible to error in estimation.
•
Current testing limited to a speed range up to
300Hz. For certain units, the limit is 250Hz; all
200‒240V units up to and including 3 HP [2.2
kW] and all 380‒480V units up to and including
5.4 HP [4 kW].
•
Current testing limited to a machine power size
up to 30 HP [22 kW].
•
Prepared for salient pole machine (IPMSM) but
not yet verified on those types of machine.
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