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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.
[0]
*
Disabled
No function
[1]
Enabled
Enables the Adjustable frequency drive
to “catch” and control a spinning motor.
When
1-73 Flying Start
is enabled,
1-71 Start Delay
and
1-72 Start Function
have no function.
[2]
Enabled Always
[3]
Enabled Ref. Dir.
[4]
Enab. Always
Ref. Dir.
NOTE!
This parameter cannot be adjusted while motor is running.
NOTE!
This function is not recommended for hoisting
applications.
For power levels above 75 hp [55 kW], flux mode must be
used to achieve the best performance.
NOTE!
To obtain the best flying start performance the advanced
motor data, parameters 1-30 through 1-35, must be
correct.
1-74 Start Speed [RPM]
Range:
Function:
Application
dependent
*
[0 - 600 RPM] This parameter can be used
for hoist applications (cone
rotor).
1-75 Start Speed [Hz]
Range:
Function:
Application
dependent
*
[Application
dependant]
This parameter can be used for
hoist applications (cone rotor).
Set a motor start speed. After the
start signal, the output speed
leaps to set value. Set the start
function in
1-72 Start Function
to
[3], [4] or [5], and set a start
delay time in
1-71 Start Delay
.
1-76 Start Current
Range:
Function:
0.00
A
*
[Application
dependant]
Some motors, e.g., cone rotor motors,
need extra current/starting speed to
1-76 Start Current
Range:
Function:
disengage the rotor. To obtain this
boost, set the required current in
1-76 Start Current
. Set
1-74 Start Speed
[RPM]
. Set
1-72 Start Function
to [3] or
[4], and set a start delay time in
1-71 Start Delay
.
This parameter can be used for hoist
applications (cone rotor).
3.3.8 1-8* Stop Adjustments
1-80 Function at Stop
Option:
Function:
Select the Adjustable frequency drive
function after a stop command or after the
speed is ramped down to the settings in
1-81 Min Speed for Function at Stop [RPM]
.
[0]
*
Coast
Leaves motor in free mode. The motor is
disconnected from the Adjustable frequency
drive.
[1]
DC hold
Energizes motor with a DC holding current
(see
2-00 DC Hold Current
).
[2]
Motor check
Checks if a motor has been connected.
[3]
Pre-
magnetizing
Builds up a magnetic field while the motor
is stopped. This allows the motor to
produce torque quickly at subsequent start
commands (asynchronous motors only). This
pre-magnetizing function does not help the
very first start command. Two different
solutions are available to pre-magnetize the
machine for the first start command:
1. Start the Adjustable frequency
drive with a 0RPM reference and
wait 2 to 4 rotor time constants
(see below) before increasing the
speed reference.
2a. Set 1-71 Start Delay to the
desired pre-mag time (2 to 4 rotor
time constants - see below).
2b. Set 1-72 to either [0] DC-hold
or [1] DC Brake.
Set the DC hold or DC brake
current magnitude (2-00 or 2-01) to
be equal to I_pre-mag = Unom /
(1.73 x Xh)
Sample rotor time constants =
(Xh+X2) / (6.3*Freq_nom*Rr)
Parameter Descriptions
FC 300 Programming Guide
3-22
MG33MD22 - VLT
®
is a registered Danfoss trademark
3
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