WEG CFW300 V1.3X, Programming Manual

Page: 87 / 157

Functions Common to All the Control Modes
CFW300 | 11-7
11
11.3 FLYING START / RIDE-THROUGH
The Flying Start function allows driving a motor that is in free running, accelerating it from the rotation in which it
is. The Ride-Through function allows recovering the inverter, with no locking by undervoltage, when there is an
instant drop in the power supply.
Both functions assume the special case in which the motor is running in the same direction and at a frequency
close to the frequency reference, thus, by immediately applying the frequency reference to the output and increasing
the output voltage in ramp, the slip and the starting torque are minimized.
P320 - Flying Start (FS) / Ride Through (RT)
Adjustable
Range:
0 = Inactive
1 = Flying Start
2 = Flying Start / Ride-Through
3 = Ride-Through Factory
Setting:
0
Properties: cfg
Description:
Parameter P320 selects the use of the Flying Start and Ride-Through functions. More details in the following
sections.
P331 - Voltage Ramp for FS and RT
Adjustable
Range:
0.2 to 60.0 s
Factory
Setting:
2.0 s
Properties:
Description:
This parameter determines the rising time of the output voltage during the execution of the Flying Start and
Ride-Through functions.
P332 - Dead Time
Adjustable
Range:
0.1 to 10.0 s Factory
Setting:
1.0 s
Properties:
Description:
Parameter P332 sets the minimum time the VSD will wait until driving the motor again with the Ride Through
function, which is necessary to demagnetize the motor.
11.3.1 Flying Start Function
In order to activate this function, just program P320 in 1 or 2; thus the inverter will impose a fixed frequency at
the start, defined by the frequency reference, and apply the voltage ramp defined in parameter P331. In this way,
the start current is reduced. On the other hand, if the motor is at rest, the frequency reference and the real frequency
of the motor are very different or the direction of rotation is inverted; the result in such cases may be worse than the
conventional start without Flying Start.
The Flying Start function is applied on loads with high inertia or systems that require start with the motor
spinning. Besides, the function may be deactivated dynamically by a digital input P263 to P266 programmed
for "24 = Disable Flying Start". In this way, the user may activate the function in a convenient way according to
the application.