1-71 Start Delay
Range: Function:
00
s*
[0 -
120 s]
When the frequency converter receives the start
command, it delays the motor start for the
period of time specified in this parameter.
The function selected in parameter 1-80 Function
at Stop is active in the delay period.
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 parameter 1-73 Flying Start is enabled,
parameter 1-71 Start Delay has no function.
Search direction for flying start is linked to the
setting in parameter 4-10 Motor Speed Direction.
[0] Clockwise: Flying start search in clockwise
direction. If not successful, a DC brake is carried
out.
[2] Both Directions: The flying start first makes a
search in the direction determined by the last
reference (direction). If not finding the speed, it
makes a search in the other direction. If not
successful, a DC brake is activated in the time set
in 2-02 DC Braking Time. Start then takes place
from 0 Hz.
[0] Disabled
Select [0] Disable if this function is not required
[1] Enabled
Select [1] Enable 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 is always estimated as
the first thing after an active start signal is given. Based on
the setting of 1-70 PM Start Mode the following happens:
1-70 PM Start Mode = [0] Rotor Detection:
If the speed estimate comes out as greater than 0 Hz, the
frequency converter catches the motor at that speed and
resume normal operation. Otherwise, the frequency
converter estimates 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
is engaged (see 2-06 Parking Current and 2-07 Parking
Time). Otherwise, the frequency converter catches the
motor at that speed and resume normal operation. Refer
to description of 1-70 PM Start Mode for recommended
settings.
Current limitations of the flystart principle used for PM
motors:
•
The speed range is up to 100% nominal speed or
the field weakening speed (which ever is lowest).
•
PMSM with high back EMF (>300 VLL(rms)) and
high winding inductance(>10 mH) 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
300 Hz. For certain units the limit is 250 Hz; all
200-240 V units up to and including 2.2 kW and
all 380-480 V units up to and including 4 kW.
•
Current testing limited to a machine power size
up to 22 kW.
•
Pred for salient pole machine (IPMSM) but not yet
verified on those types of machine.
•
For high-inertia applications (i.e. where the load
inertia is more than 30 times larger than the
motor inertia) a brake resistor is recomended to
avoid overvoltage trip during high speed
engagement of the flystart function.
How to Programme VLT HVAC Drive FC 102 Operating Instructions
MG11F402 - Rev. 2013-12-16 93
6 6
To Next Page
Loading...
Need help?
General