Fuji Electric FRENIC-MEGA, Инструкция по эксплуатации

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Even if you select "Trip after decelerate-to-stop" or "Continue to run," the inverter may not be able to do so when
the load's inertia is small or the load is heavy, due to undervoltage caused by a control delay. In such a case, when
"Trip after decelerate-to-stop" is selected, the inverter allows the motor to coast to a stop; when "Continue to run"
is selected, the inverter saves the output frequency being applied when the undervoltage alarm occurred and restarts
at the saved frequency after a recovery from the momentary power failure.
When the input power voltage for the inverter is high, setting the continuous running level high makes the control
more stable even if the load's inertia is relatively small. Raising the continuous running level too high, however,
might cause the continuous running control activated even during normal operation.
When the input power voltage for the inverter is extremely low, continuous running control might be activated
even during normal operation, at the beginning of acceleration or at an abrupt change in load. To avoid this, lower
the continuous running level. Lowering it too low, however, might cause undervoltage that results from voltage
drop due to a control delay.
Before you change the continuous running level, make sure that the continuous running control will be performed
properly, by considering the fluctuations of the load and the input voltage.
F15, F16 Frequency Limiter (High), Frequency Limiter (Low)
H63 Low Limiter (Mode selection)
„ Frequency Limiter (High and Low) (F15, F16) Data setting range: 0.0 to 500.0 (Hz)
F15 and F16 specify the upper and lower limits of the output frequency or reference frequency, respectively. The object to
which the limit is applied differs depending on the control system.
Frequency Limiter
Object to which the limit is applied
V/f control Vector control without/with speed sensor
Frequency Limiter (High) F15 Output frequency Reference speed (reference frequency)
Frequency Limiter (Low) F16 Reference frequency Reference speed (reference frequency)
When the limit is applied to the reference frequency or reference speed, delayed responses of control may
cause an overshoot or undershoot, and the frequency may temporarily go beyond the limit level.
„ Low Limiter (Mode selection) (H63)
H63 specifies the operation to be carried out when the reference frequency drops below the low level specified by F16, as
follows:
Data for H63 Operation
0 The output frequency will be held at the low level specified by F16.
1 The inverter decelerates to stop the motor.
(H63 = 0) (H63 = 1)
• When you change the frequency limiter (High) (F15) in order to raise the reference frequency, be sure to change
the maximum frequency (F03) accordingly.
• Maintain the following relationship among the data for frequency control:
F15 > F16, F15 > F23, and F15 > F25
F03 > F16
where, F23 and F25 specify the starting and stop frequencies, respectively.
If you specify any wrong data for these function codes, the inverter may not run the motor at the desired speed,
or cannot start it normally.