Mitsubishi Electric FR-A700 Instruction Manual page 395

Parameter
Set multiple electronic thermal relay functions (Pr. 51)
Use this function when rotating two motors of different rated currents individually by a single
inverter. (When rotating two motors together, use external thermal relays.)
Set the rated current of the second motor in Pr. 51. When the RT signal is on, thermal protection
is provided based on the Pr. 51 setting.
Pr. 450
Second applied
motor
9999
9999
≠ 9999
≠ 9999
Tab. 6-44: Switching of the electronic thermal relay
¼
Output current value is used to perform integration processing.
Output current is assumed as 0A to perform integration processing. (cooling processing).
— Electronic thermal relay function is not activated.
NOTES
The RT signal acts as the second function selection signal and makes the other second
functions valid.
The RT signal is assigned to the RT terminal in the initial setting. By setting "3" in any of
Pr. 178 to Pr. 189 "Input terminal function selection", you can assign the RT signal to the
other terminal.
FR-A700 EC
M
3~
M
3~
Pr. 9
Electronic thermal Second electronic
O/L relay thermal O/L relay
0
0.01 to 500 (0.1 to 3600)
≠ 0
0.01 to 500 (0.1 to 3600)
0
0.01 to 500 (0.1 to 3600)
≠ 0
0.01 to 500 (0.1 to 3600)
Selection and protection of a motor
Fig. 6-89:
Operating two motors by a single inverter
RT = OFF
Pr. 51
First
Motor
9999 —
0 —
—
¼
9999
¼
0
¼
9999 —
0 —
—
¼
9999
¼
0
¼
I001137C
RT = ON
Second First Second
Motor Motor Motor
— — —
— — —
¼
—
¼
— —
— —
¼
— — —
— — —
¼
—
¼
— —
¼
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