Mitsubishi Electric F700 User Manual

209
Special operation and frequency control
4
PARAMETERS
4.20.2 Bypass-inverter switchover function (Pr. 135 to Pr. 139, Pr. 159)
⋅ 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 alarm. 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 complicated sequence circuit for bypass-inverter switchover 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
Description
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 an alarm 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 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 to 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 inverter 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 156.)

Mitsubishi Electric F700 Specifications

General

Brand	Mitsubishi Electric
Model	F700
Category	Inverter
Language	English