Mitsubishi Electric FR-F720-00046 Instruction Manual page 249

Special operation and frequency control
(2) Electronic bypass operation sequence
⋅ Operation sequence example when there is no automatic switchover sequence (Pr. 139 = "9999")
ON
Power supply
OFF
Operation interlock ON
(MRS) OFF
Inverter run command ON
(STF) OFF
ON
Inverter/bypass (CS)
OFF
ON
Inverter input side MC
(MC1)
OFF
ON
Inverter output side MC
(MC3)
OFF
ON
MC for bypass
operation (MC2)
OFF
Each timer
Operating status
(motor speed)
⋅ Operation sequence example when there is automatic switchover sequence (Pr. 139 ≠ "9999", Pr. 159 = "9999")
STF
Output frequency Pr.139
Frequency command
Actual motor speed
INV
MC3
operation
Bypass
MC2
operation
A : Pr.136 MC switchover interlock time
C : Pr.57 Restart coasting time
⋅ Operation sequence example when there is automatic switchover sequence (Pr. 139 ≠ "9999", Pr. 159 ≠ "9999")
ON
STF
OFF
Output frequency Pr.139
Frequency command
Actual motor speed
ON
INV
MC3
operation
OFF
ON
Bypass
MC2
operation
OFF
A : Pr.136 MC switchover interlock time
C : Pr.57 Restart coasting time
240
Off only at inverter fault
Pr.136
Pr.57
INV
Coasting
operation
ON
OFF
ON
OFF
ON
OFF
C A
C A
B : Pr.137 Start waiting time
D : Pr.58 Restart cushion time
Pr.137 Pr.58
Pr.57
Pr.136
Bypass INV
Coasting Stop
operation
operation
B : Pr.137 Start waiting time
D : Pr.58 Restart cushion time
Pr.159
A B C D A
ON : Operation enabled
OFF: Operation disabled
ON : Forward rotation
OFF: Stop
ON : Inverter operation
OFF: Bypass operation
Indicates the delay time until
the MC turns on (off).
Pr.136 MC switchover interlock time
Pr.137 MC3 start (waiting time)
Pr.57 reset time
Pr.58 Switchover cushion time
Time
Time
A B C D
A B C D
Time
Time