Flying Start Function; Ride-Through Function - WEG CFW100 Programming Manual

P320 – Flying Start (FS) / Ride Through (RT)
Adjustable
0 = Inactive
Range:
1 = Flying Start
2 = Flying Start / Ride-Through
3 = Ride-Through
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
0.2 to 60.0 s
Range:
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 0.1 to 10.0 s
Range:
Properties:
Description:
Parameter P332 sets the minimum time the inverter will wait until driving the motor again, which is necessary
for the demagnetization of the motor.
For the Ride-Through function, the time is counted as of the line drop. However, in the actuation of the Flying
Start function, the count starts after the application of the "Run/Stop = Run" command.

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.

11.3.2 Ride-Through Function

The Ride-Through function will disable the inverter output pulses (IGBT) as soon as the supply voltage reaches a
value below the undervoltage value. A fault due to undervoltage (F021) does not occur and the DC link voltage will
slowly drop until the supply voltage returns. In case it takes the supply voltage too long to return (over 2 seconds),
the inverter may indicate F021 (undervoltage on the DC link). If the supply voltage returns before, the inverter will
enable the pulses again, imposing the frequency reference instantly (like in the Flying Start function) and making a
voltage ramp with time defined by parameter P331. Refer to
Functions Common to All the Control Modes
Figure 11.6 on page
Return Advance
Factory
0
Setting:
Factory
2.0 s
Setting:
Factory 1.0 s
Setting:
11-8.
CFW100 | 11-7
11