Danfoss VLT AutomationDrive FC 302 Programming Manual page 52

Parameter Descriptions
1-73 Flying Start
Option:
[2] Enabled
3 3
Always
[3] Enabled Ref.
Dir.
[4] Enab. Always
Ref. Dir.
NOTICE
This function is not recommended for hoisting
applications.
For power levels above 55 kW, flux mode must be used
to achieve the best performance.
NOTICE
To obtain the best flying start performance the advanced
motor data, parameter 1-30 Stator Resistance (Rs) to
parameter 1-35 Main Reactance (Xh), must be correct.
1-74 Start Speed [RPM]
Range:
Size [0 -
related 600
*
RPM]
1-75 Start Speed [Hz]
Range:
Size [ 0 -
related 500.0
*
Hz]
1-76 Start Current
Range:
0 [ 0 -
A par.
*
1-24 A]
50
VLT
Function:
parameter 1-72 Start Function have no
function.
Function:
Set a motor start speed. After the start
signal, the output speed leaps to set value.
Set the start function in
parameter 1-72 Start Function to [3] Start
speed cw, [4] Horizontal operation or [5] VVC
+
/Flux clockwise, and set a start delay time
in parameter 1-71 Start Delay.
Function:
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 parameter 1-72 Start Function to
[3] Start speed cw, [4] Horizontal operation or
+
[5] VVC /Flux clockwise, and set a start delay
time in parameter 1-71 Start Delay.
Function:
Some motors, e.g. cone rotor motors, need extra
current/starting speed to disengage the rotor. To
obtain this boost, set the required current in
parameter 1-76 Start Current. Set
parameter 1-74 Start Speed [RPM]. Set
parameter 1-72 Start Function to [3] Start speed cw
or [4] Horizontal operation, and set a start delay
time in parameter 1-71 Start Delay.
®
AutomationDrive FC 301/302 Programming Guide
1-76 Start Current
Range:
3.3.9 1-8* Stop Adjustments
1-80 Function at Stop
Option:
[0] Coast
*
[1] DC hold
[2] Motor check
[3] Pre-
magnetizing
MG33MI02 - Rev. 2013-11-20
Function:
This parameter can be used for hoist applications
(cone rotor).
Function:
Select the frequency converter function
after a stop command or after the speed is
ramped down to the settings in
parameter 1-81 Min Speed for Function at
Stop [RPM].
Leaves motor in free mode. The motor is
disconnected from the frequency converter.
Energises motor with a DC holding current
(see parameter 2-00 DC Hold Current).
Checks if a motor has been connected.
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-magnetising function does not help the
very first start command. 2 different
solutions are available to pre-magnetise the
machine for the first start command:
1. Start the frequency converter
with a 0 RPM reference and wait 2
to 4 rotor time constants (see
below) before increasing the speed
reference.
2a. Set parameter 1-71 Start Delay
to the desired pre-mag time (2 to
4 rotor time constants - see
below).
2b. Set parameter 1-72 Start
Function to either [0] DC-hold or [1]
DC-Brake.
Set the DC-hold or DC-brake
current magnitude
(parameter 2-00 DC Hold Current or
parameter 2-01 DC Brake Current)
to be equal to I_pre-mag = Unom/
(1.73 x Xh)
Sample rotor time constants =
(Xh+X2)/(6.3*Freq_nom*Rr)
1 kW = 0.2 s
10 kW = 0.5 s
100 kW = 1.7 s
1000 kW = 2.5 s