Mitsubishi Electric 700 Series, Instruction Manual

Page: 304 / 416

293
Special operation and frequency control
4
P
ARA
MET
E
RS
4.21 Special operation and frequency control
4.21.1 Bypass-inverter switchover function (Pr. 57, Pr. 58, Pr. 135 to Pr. 139, Pr. 159)
Purpose Parameter that must be Set
Refer
to Page
Switch between the inverter operation and
bypass operation to operate. Bypass-inverter switchover
function Pr. 57, Pr.58, Pr. 135 to Pr. 139,
Pr. 159
293
Avoid overvoltage alarm due to regeneration by
automatic adjustment of output frequency Regeneration avoidance
function
Pr. 665, Pr. 882 to Pr. 886 298
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
Number
Name
Initial
Value
Setting Range
200V class
(400V class)
Description
57 Restart coasting time 9999
0
⋅
FR-F720-00077 (FR-F740-00038) or less ............ 0.5s,
⋅
FR-F720-00105 to 00340
(FR-F740-00052 to 00170) ................................... 1s,
⋅
FR-F720-00490 to 02330
(FR-F740-00250 to 01160).................................... 3.0s,
⋅
FR-F720-03160 (FR-F740-01800) or more........... 5.0s,
The above times are coasting time.
02330
(01160)
or less
0.1 to
5s
Set the waiting time for inverter-triggered restart after an
instantaneous power failure.
03160
(01800)
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 relay
operation (E.OHT) or CPU fault (E.CPU) occurs).
139
Automatic switchover
frequency from inverter to
bypass operation
9999
0 to 60Hz
Set the frequency to switch inverter operation to bypass
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
frequency range from bypass
to 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
bypass 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 bypass
operation, operation is switched to inverter operation and the
motor decelerates to stop.
The above parameters can be set when Pr. 160 User group read selection = "0". (Refer to page 190.)