Mitsubishi FR-A800

(H) Protective function parameter
PARAMETERS
331
5
GROUP
H
5.10.1 Motor overheat protection (electronic thermal
O/L relay)
 The initial value for the FR-A820-00077(0.75K) or lower and FR-A840-00038(0.75K) or lower is set to the 85% of the rated inverter current.
 The setting range for FR-A820-03160(55K) or lower and FR-A840-01800(55K) or lower. The minimum setting increment is "0.01 A".
 The setting range for FR-A820-03800(75K) or higher, and FR-A840-02160(75K) or higher. The minimum setting increment is "0.1 A".
Set the current of the electronic thermal O/L relay function to protect the motor from overheating. Such settings will
provide the optimum protective characteristic considering the low cooling capability of the motor during low-speed
operation.
Pr. Name Initial value
Setting
range
Description
9
H000
Electronic thermal O/L
relay
Rated inverter
current

0 to 500 A
Set the rated motor current.
0 to 3600 A

600
H001
First free thermal reduction
frequency 1
9999
0 to 590 Hz
The electronic thermal O/L relay operation level can be
changed to match the motor temperature
characteristics with the combination of these three
points (Pr.600, Pr.601), (Pr.602, Pr.603), (Pr.604, Pr.9).
9999: Free thermal O/L relay invalid
9999
601
H002
First free thermal reduction
ratio 1
100%
1 to 100%
9999
602
H003
First free thermal reduction
frequency 2
9999
0 to 590 Hz
9999
603
H004
First free thermal reduction
ratio 2
100%
1 to 100%
9999
604
H005
First free thermal reduction
frequency 3
9999
0 to 590 Hz
9999
607
H006
Motor permissible load
level
150% 110 to 250%
Set the permissible load according to the motor
characteristics.
51
H010
Second electronic thermal
O/L relay
9999
0 to 500 A

Enabled when the RT signal is ON.
Set the rated motor current.
0 to 3600 A

9999 Second electronic thermal O/L relay invalid
692
H011
Second free thermal
reduction frequency 1
9999
0 to 590 Hz
The electronic thermal O/L relay operation level can be
changed to match the second motor temperature
characteristics with the combination of these three
points (Pr.692, Pr.693), (Pr.694, Pr.695), (Pr.696,
Pr.51).
9999: Second free thermal O/L relay invalid
9999
693
H012
Second free thermal
reduction ratio 1
100%
1 to 100%
9999
694
H013
Second free thermal
reduction frequency 2
9999
0 to 590 Hz
9999
695
H014
Second free thermal
reduction ratio 2
100%
1 to 100%
9999
696
H015
Second free thermal
reduction frequency 3
9999
0 to 590 Hz
9999
608
H016
Second motor permissible
load level
9999
110 to 250% Set the permissible load when the RT signal is ON.
9999
The Pr.607 setting is applied even when the RT signal
is ON.
561
H020
PTC thermistor protection
level
9999
0.5 to 30 k Set the PTC thermistor protection level (resistance).
9999 PTC thermistor protection disabled
1016
H021
PTC thermistor protection
detection time
0 s 0 to 60 s
Set the time from when the resistance of the PTC
thermistor reaches the protection level until the
protective function is activated.