Mitsubishi Electric FR-A700 Series, Техническое руководство, Страница: 382 / 550

416
PARAMETER
2.20.6 Bypass-inverter switchover function [Pr. 57, 58, 135 to 139, 159]
(common)
The complicated sequence circuit for bypass-inverter
switchover is built-in to the inverter. Hence, simply inputting
the start, stop or automatic switchover selection signal facilitates the interlock operation of the switchover
magnetic contactor.
When the motor is operated at 60Hz (or 50Hz), more
efficient operation can be performed by the commercial
power supply than by the inverter. When the motor cannot
be stopped for a long time for the maintenance/inspection
of the inverter, it is recommended to provide the
commercial power supply circuit.
To switch between inverter operation and bypass
operation, an interlock must be provided to stop the motor
once and then start it by the inverter in order to prevent the
inverter from resulting in an overcurrent fault. Using the electronic bypass sequence function that outputs
the timing signal for operation of the magnetic contactor, a
complicated commercial power supply switchover interlock
can be provided by the inverter.
The electronic bypass sequence function is valid only in
the external operation or combined operation mode (PU
speed command, external operation command [
Pr. 79 = 3
]).
Commercial operation can not be performed with the
Mitsubishi vector motor (SF-V5RU).
A700 F700
[Pr.] Name Initial Value Setting Range Description
57 Restart coasting time 9999
0
1.5K or less............ 0.5s
2.2K to 7.5K ........... 1s
11K to 55K ............. 3.0s
75K or more ........... 5.0s
of coasting time
55K or
less
0.1 to
5s Set the waiting time for inverter-triggered restart after an
instantaneous power failure.
75K or
more
0.1 to
30s
9999 No restart
58 Restart cushion time 1s 0 to 60s Set a voltage starting time at restart.
135
Electronic bypass sequence
selection
0
0 Without electronic bypass sequence
1 With electronic bypass sequence
136 MC switchover interlock time 1s 0 to 100s Set the operation interlock time of MC2 and MC3.
137 Start waiting time 0.5s 0 to 100s
Set the time slightly longer (0.3 to 0.5s or so) than the time from
when the ON signal enters MC3 until it actually turns ON.
138 Bypass selection at a fault 0
0 Inverter output is stopped (motor coast) at inverter fault.
1
Operation is automatically switched to bypass operation at
inverter fault (not switched when an external thermal error
occurs)
139
Automatic switchover frequency
from inverter to bypass operation
9999
0 to 60Hz
Set the frequency to switch the inverter operation to commercial
power supply operation.
Inverter operation is performed from a start until [
Pr. 139 ] is
reached, and when the output frequency is at or above [ Pr. 139 ],
inverter operation is automatically switched to bypass operation.
9999 Without automatic switchover
159
Automatic switchover ON range
between commercial power-
supply and inverter operation
9999
0 to 10Hz
Valid during automatic switchover operation ([ Pr. 139 9999 ])
When the frequency command decreases below ([
Pr. 139
] - [
Pr.
159
]) after operation is switched from inverter operation to
commercial power supply operation, the inverter automatically
switches operation to inverter operation and operates at the
frequency of frequency command. When the inverter start
command (STF/STR) is turned OFF, operation is switched to
inverter operation also.
9999
Valid during automatic switchover operation ([ Pr. 139 9999 ])
When the inverter start command (STF/STR) is turned OFF
after operation is switched from inverter operation to
commercial power supply operation, operation is switched to the
inverter operation and the motor decelerates to stop.