Overheat Protection Of The Motor By The Inverter (Pr. 9) - Mitsubishi Electric FR-A700 Instruction Manual

Before operation
3.3.2

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
Number
9 Electronic thermal O/L relay
*1 Refer to page 158 for the rated inverter current value.
The initial values of the 0.4K and 0.75K are set to 85% of the rated inverter current.
*2 The minimum setting increments are 0.01A for the 55K or less and 0.1A for the 75K or more.
Changing example
Change the Pr. 9 Electronic thermal O/L relay setting to 7.5A according to the motor rated current.
(FR-A720-1.5K)
1.
Screen at powering on
The monitor display appears.
2.
Press
operation mode.
3.
Press
setting mode.
4.
Turn
thermal O/L relay appears.
5.
Press
set value.
6.
Turn
"
to
7.
Press
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 section 4 of
Instruction Manual (applied).
48
Name Initial Value
Inverter rated
current
Operation
to choose the PU
to choose the parameter
until Pr. 9 Electronic
to show the currently
(8A for FR-A720-1.5K)
to change the set value
". (7.5A)
to set.
By turning , you can read another parameter.
·
Press to show the setting again.
·
Press twice to show the next parameter.
·
Setting Range
55K or less
75K or more 0 to 3600A
*1
Display
PU indication is lit.
Flicker Parameter setting complete!!
···
Description
*2
0 to 500A
Set the rated motor current.
The parameter number
read previously appears.
Refer to page
158 for initial
value of the
inverter rated
current.