Fuji Electric FRENIC-MEGA, Инструкция по эксплуатации

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5-54
Ch
ap
. 5
FUNCTION C
O
DES
F codes
During a momentary power failure, the motor slows down. After power is restored, the inverter restarts at the frequency just
before the momentary power failure. Then, the current limiting function works and the output frequency of the inverter
automatically decreases. When the output frequency matches the motor speed, the motor accelerates up to the original output
frequency. See the figure below. In this case, the instantaneous overcurrent limiting must be enabled (H12 = 1).
• Auto-restarting after momentary power failure IPF
This output signal is ON during the period after the occurrence of momentary power failure until the completion of restart
(the output has reached the reference frequency). When the
IPF
is ON, the motor slows down, so perform necessary
operations. ( For details about
IPF
, refer to E20 through E24 and E27 (data = 6).)
„ Restart mode after momentary power failure (Basic operation with auto search enabled)
Auto search for idling motor speed will become unsuccessful if it is done while the motor retains residual voltage. It is,
therefore, necessary to leave the motor for the time (auto search delay time) enough to discharge the residual voltage. The
delay time is specified by H46 (Starting Mode (Auto search delay time 2)).
The inverter will not start unless the time specified by H46 has elapsed, even if the starting conditions are satisfied. (
For
details, refer to H09 and d67.)
• To use auto search for idling motor speed, it is necessary to tune the inverter beforehand.
• When the estimated speed exceeds the maximum frequency or the upper limit frequency, the inverter disables
auto search and starts running the motor with the maximum frequency or the upper limit frequency, whichever is
lower.
• During auto search, if an overcurrent or overvoltage trip occurs, the inverter restarts the suspended auto search.
• Perform auto search at 60 Hz or below.
• Note that auto search may not fully provide the performance depending on load conditions, motor parameters,
wiring length, and other external factors.
• Do not execute motor tuning with output filter unless the filter is a reactor type only. A tuning error may result if
any other type filter is in use.