Bypass-Inverter Switchover Function (Pr. 57, Pr. 58, Pr. 135 To Pr. 139, Pr. 159) - Mitsubishi Electric FR-A720-0.4K Instruction Manual

4.25.2 Bypass-inverter switchover function (Pr. 57, Pr. 58, Pr. 135 to Pr. 139, Pr. 159)

The complicated sequence circuit for bypass operation is built in the inverter. Hence, merely inputting the start,
stop or automatic switchover selection signal facilitates the interlock operation of the switchover magnetic
contactor.
Parameter
Name
Number
57 Restart coasting time
58 Restart cushion time
Electronic bypass
135
sequence selection
MC switchover interlock
136
time
137 Start waiting time
Bypass selection at a
138
fault
Automatic switchover
139 frequency from inverter
to bypass operation
Automatic switchover
frequency range from
159
bypass to inverter
operation
⋅ 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 avoid commercial power supply being applied to the inverter output side when switching between inverter
operation and commercial power supply operation, provide an interlock which the MC of the commercial power
supply side turns ON only when the MC of the inverter output side is OFF. 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.
CAUTION
Commercial operation cannot be performed with the Mitsubishi vector motor (SF-V5RU).
Initial
Setting Range
Value
⋅ 1.5K or lower..................................................... 0.5s,
⋅ 2.2K to 7.5K
⋅ 11K to 55K
0
⋅ 75K or higher .................................................... 5.0s,
The above times are coasting time.
9999
55K or 0.1 to
lower 5s
Set the waiting time for inverter-triggered restart after an
instantaneous power failure.
75K or 0.1 to
higher 30s
9999 No restart
1s 0 to 60s Set a voltage starting time at restart.
0 Without electronic bypass sequence
0
1 With electronic bypass sequence
1s 0 to 100s Set the operation interlock time of MC2 and MC3.
Set the time slightly longer (0.3 to 0.5s or so) than the time from
0.5s 0 to 100s
when the ON signal enters MC3 until it actually turns ON.
0 Inverter output is stopped (motor coast) at inverter fault.
Operation is automatically switched to bypass operation at
0
1 inverter fault (Not switched when an external thermal relay
operation (E.OHT) or CPU fault (E.CPU) occurs).
Set the frequency to switch inverter operation to bypass
operation.
Inverter operation is performed from a start until Pr. 139 is
0 to 60Hz
reached, and when the output frequency is at or above Pr.
9999
139, inverter operation is automatically switched to bypass
operation.
9999 Without automatic switchover
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
bypass operation, the inverter automatically switches
0 to 10Hz
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
9999
inverter operation also.
Valid during automatic switchover operation (Pr. 139 ≠ 9999)
When the inverter start command (STF/STR) is turned OFF
9999
after operation is switched from inverter operation to bypass
operation, operation is switched to inverter operation and
the motor decelerates to stop.
Special operation and frequency control
Description
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1s,
3.0s,
4
369