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F-22
[Adjustment value]
VF-A7 searches the motor speed and restarts. It detects the motor speed also at
the time of a power supply injection. This method needs setting of motor constant
parameters. Activation of zero speed motor needs waiting times.
It starts from the frequency, when coast started in instant electric power failure, ST
terminal OFF, etc... Usual starting is performed at the time of a power supply
injection and after (Control circuit insufficient voltage) detection, at the time
of a trip reset.
It starts from the frequency, when coast started in instant electric power failure, ST
terminal OFF, etc. It starts on setting frequency (speed reference frequency) at the
time of a power supply injection and after (Control circuit insufficient voltage)
detection, at the time of a trip reset.
This setting is used for the models 37kW or more. Do not set it as = for
other models. If it is set as = from a model 30kW or less, since the
rotational frequency of a motor is normally undetectable, there is a possibility that
trips, such as an over-current, overload, and an over-voltage, may occur.
The rotational speed and the rotation direction of a motor are searched It searches
also at the time of a power supply injection. The time taken to detect the rotational
speed of a motor becomes short as compared with the speed search #1.
Use at factory default setting (0.4~30kW:= 37~280kW:=).
The setting =, is for short time starting without speed searching to save
waiting times(*1). It may give the machine load of torque momentarily so use it
carefully.
Caution!
By using retry function together, auto restart function can be actuated at the time of
tripping.
Adaptation for elevator applications
The load may go down in the waiting time after operation start signal is inputted until it starts.
When you apply an inverter to an elevator, make the setting as =. And do not use
the retry function.
In the case the auto restart function does not work
When a trip occur at the time of auto restart, or auto restart function does not work well,
please adjust parameters referring to step 3.
(*1)Case
For the sake of motor speed detection after the power restoration, there are following waiting
times(longest time) at time of auto restart.
When the auto restart function is selected, the this function is actuated also at time of
activation of motor and at the first operation after the reset of tripping. The operation will
restart after the waiting time passes.
Before using the auto restart function, be sure to confirm the setting value of the motor
constant parameters; ,
If the wrong setting value is used, motor speed cannot be searched and tripping accident
such as over-current, overload, over-voltage, etc. can occur.
In the case of the combination with a motor smaller two or more frames than inverter rated
capacity, this function may be unable to detect the rotational speed of the motor.
You cannot use a smaller capacity motor for check of operation etc., please be careful.
Even when the auto restart function is selected, motor speed may not be detected if the
frequency is more than 60[Hz]. In this case, tripping accident such as over-current, overload,
over-voltage, etc. can occur.
If the motor is idle state and motor-load is light, the motor may rotate a little. Be careful.
Speed search #1
Restart at coasted frequency #1
Restart at coasted frequency #2
Speed search #2
Type of inverter waiting times (longest time) [s]
VFA7-2004PL 2037PL 4007PL 4037PL
About 2
VFA7-2055PL 2300P 4055PL 4300P
About 4