(A) Application parameters
Connect the control power (R1/L11, S1/L21) in front of the input-side MC1. If the control power is
connected behind the input-side MC1, the electronic bypass sequence function will not operate.
The electronic bypass sequence function is only enabled when Pr. 135 = "1" and in the External
operation mode or combined operation mode (PU speed command and External operation com-
mand with Pr. 79 = "3"). MC1 and MC3 turn ON when Pr. 135 = "1" and in an operation mode other
than mentioned above.
MC3 turns ON when the MRS and CS signals are ON and the STF(STR) signal is OFF. If the motor
was coasted to a stop from commercial power supply operation at the previous stop, the motor
starts running only after waiting the time set in Pr. 137.
Inverter operation is only available when the MRS, STF(STR), and CS signals are ON. In all other
cases (when the MRS signal is ON), commercial power supply operation is available.
When the CS signal is OFF, the motor switches to the commercial power supply operation. How-
ever, when the STF(STR) signal is OFF, the motor decelerates to a stop during inverter operation.
From the point where MC2 and MC3 are both turned OFF, there is a waiting time set in Pr. 136, till
MC2 or MC3 is turned ON.
Even when the electronic bypass sequence is enabled (Pr. 135 = "1"), the Pr. 136 and Pr. 137 set-
tings are ignored in PU operation mode.
In addition, the input terminals (STF, CS, MRS, OH) return to perform their normal functions.
When the electronic bypass sequence function (Pr. 135 = "1") and PU operation interlock function
(Pr. 79 = "7") are used at the same time, the MRS signal is shared with the PU operation external
interlock if the X12 signal is not assigned. (The inverter operation is available when the MRS and
CS signals are ON.)
Set the acceleration time to the level that does not activate the stall prevention operation.
When switching to the commercial power supply operation while a failure such as an output short
circuit is occurring between the magnetic contactor MC3 and the motor, the damage may further
spread. When a failure occurs between the MC3 and motor, make sure to provide a protection cir-
cuit, such as using the OH signal input.
Changing the terminal functions with Pr. 178 to Pr. 189 and Pr. 190 to Pr. 196 may affect other
functions. Set parameters after confirming the function of each terminal.
Switching with the electronic bypass sequence is not available during retry. Switching occurs after
the retry. When the electronic bypass is valid at a fault (Pr. 138 = "1"), switching occurs also during
When the electronic bypass sequence function and the retry function of the converter unit are
used at the same time for the separated converter type, set 101 or more in the number of retries at
fault occurrence (Pr.67) on the converter unit side.
When a value less than 100 is set, ALM signal does not turn ON until the retry count is exceeded. In
this case, the electronic bypass at a fault is not performed until the retry count is exceeded.
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