Flying Start; Normal/High Overload Torque Control, Open Loop - Danfoss AKD 5001 Manual

Flying start

This function makes it possible to "catch" a motor
that is spinning freely and for the frequency converter
to take control of the motor speed. This function can
be enabled or disabled via parameter 445.
If flying start has been selected, there will be four
situations in which the function is activated:
1. After a coast has been given via terminal 27.
2. After power-up.
3. If the frequency converter is in a trip state and
a reset signal has been given.
4. If the frequency converter releases the motor
because of a fault state and the fault disappears
before a trip, the frequency converter will catch
the motor and go back to the reference.
1. Flying start is active.
2. Flying start is active.
The search sequence for the spinning motor depends
on Rotation, frequency/direction (parameter 200). If
only clockwise is selected, the frequency converter will
start looking from Maximum frequency (parameter 202)
down to 0 Hz. If the frequency converter does not find
the spinning motor during the search sequence, it will
carry out a DC braking so as to try to bring the speed
of the spinning motor down to 0 rpm. This requires that
MG.50.R3.02 -
AKD 5000
the DC brake is active via parameters 125 and 126. If
Both directions is selected, the frequency converter will
first find out in which direction the motor rotates and
then search for the frequency. If the motor is not found,
the system assumes that the motor is at a standstill or
is rotating at a low speed, and the frequency converter
will start the motor in the normal way after searching.
3. The frequency converter trips and Flying
start is active.
4. The frequency converter momentarily
releases the motor. Flying start is activated
and catches the motor again.

Normal/high overload torque control, open loop

This function enables the frequency converter to perform
a constant 100% torque, using an oversize motor.
The choice between a normal or a high overload torque
characteristic is made in parameter 101.
This is also where to choose between a high/normal
constant torque characteristic (CT) or a high/normal
VT torque characteristic
If a high torque characteristic is chosen, a rated
motor with the frequency converter obtains up to
160% torque for 1 min. in both CT and VT. If a
normal torque characteristic is chosen, an oversize
motor allows up to 110% torque performance for up
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