Mitsubishi Electric FR-A700 Technical Manual page 535

4.5 Inverter - commercial power supply switch-over
operation
4.5.1 Star-Delta connection start
When the motor is rotated at full speed of 60Hz (or 50Hz), running the motor by commercial power supply is more efficient
than inverter operation. Also, 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.
MCCB
Power
supply
Forward rotation start
Frequency setting
potentiometer
2W1k
*1 For the control circuit, refer to page 570 and 572.
*2 For inverter operation, turn ON MC2 and MCD simultaneously. (
*3 Provide electrical and mechanical interlocks to prevent the MC1 and MC2 from being turned ON at the same time.
*4 In principle, do not turn ON the MC2 to start the inverter while the motor is rotating (coasting). Refer to page 37 for details of the
magnetic contactor (MC2) turn-ON conditions.
*5 Before making connection, ensure that the phase rotation of the commercial power supply is in R
common
(common)
common
(common)
MC1
R
S
T
Inverter
MC
R U
S
V
T
W
STF
SD
10
2
5
*5
OCR
MI
*3
MC2
Y
-connection operation cannot be performed.)
569
PRACTICAL CIRCUITS
Motor
U
IM
V
W
Y Z X
MCD MCY
S T sequence.
4