Overheat Protection Of The Motor By The Inverter (Pr. 9) - Mitsubishi Electric FR-A701 Instrucion Manual

4.3.2

Overheat protection of the motor by the inverter (Pr. 9)

Set the rated motor current in Pr. 9 Electronic thermal O/L relay to protect the motor from overheat.
Parameter
Name
Number
9 Electronic thermal O/L relay
*1 Refer to page 174 for the rated inverter current value.
*2 The minimum setting increments are 0.01A.
Changing example
Change the Pr. 9 Electronic thermal O/L relay setting to 22A according to the motor rated current.
(FR-A721-5.5K)
1.
Screen at powering on
The monitor display appears.
2.
Press
mode.
3.
Press
setting mode.
4.
Turn
thermal O/L relay appears.
5.
Press
set value.
6.
Turn
to "
7.
Press
REMARKS
· Since a thermal protector is provided for a vector control dedicated motor (SF-V5RU), set "0" in Pr. 9.
CAUTION
· Protective function by electronic thermal relay function is reset by inverter power reset and reset signal input. Avoid
unnecessary reset and power-off.
· When two or more motors are connected to the inverter, they cannot be protected by the electronic thermal relay function.
Install an external thermal relay to each motor.
· When the difference between the inverter and motor capacities is large and the setting is small, the protective characteristics of
the electronic thermal relay function will be deteriorated. In this case, use an external thermal relay.
· A special motor cannot be protected by the electronic thermal relay function. Use an external thermal relay.
· PTC thermistor output built-in the motor can be input to the PTC signal (AU terminal). For details, refer to chapter 4 of
instruction manual (applied).
Initial Value
Inverter rated
current
Operation
to choose PU operation
to choose the parameter
until Pr. 9 Electronic
to show the currently
(24A for FR-A721-5.5K)
to change the set value
". (22A)
to set.
By turning , you can read another parameter.
·
Press to show the setting again.
·
Press twice to show the next parameter.
·
Setting Range
*2
0 to 500A
*1
Display
PU indication is lit.
The parameter number
read previously appears.
Flicker Parameter setting complete!!
···
Before operation
Description
Set the rated motor current.
Refer to page
174 for initial
value of the
inverter rated
current.
4
the
57