Selection And Protection Of A Motor; Motor Overheat Protection (Electronic Thermal O/L Relay, Ptc Thermistor Protection) (Pr. 9, Pr. 561, Pr.600 To Pr.604) - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

4.9

Selection and protection of a motor

Purpose
Motor protection from overheat
To set the overheat protection
characteristics for the motor
To select the motor to be used
To run by maximizing the
performance of the motor
4.9.1 Motor overheat protection (Electronic thermal O/L relay, PTC thermistor protection)
(Pr. 9, Pr. 561, Pr.600 to Pr.604)
Set the current of the electronic thermal relay function to protect the motor from overheat. This feature provides the
optimum protective characteristics, including reduced motor cooling capability, at low speed.
Parameter
Name
Number
Electronic thermal O/L
9
relay
PTC thermistor protection
561
level
600
Free thermal reduction
speed 1
601
Free thermal reduction
ratio 1
602
Free thermal reduction
speed 2
603
Free thermal reduction
ratio 2
604
Free thermal reduction
speed 3

These parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 161.)

Refer to page 288 for the rated motor current.

The value left of the slash is for the 2.2K drive unit or lower. The one right of the slash is for the 3.7K drive unit.

If a value exceeding the upper speed limit of the motor is set, the actual operation will be limited at the maximum rotation speed. The setting range is for the
S-PM motor. The maximum setting value differs depending on the number of poles of the applied motor.
........Specifications differ according to the date assembled. Refer to page 294 to check the SERIAL number.
Parameter that should be Set
Electronic thermal O/L relay
PTC thermistor protection
Free thermal O/L relay
setting
Applied motor
Offline auto tuning
Initial Value Setting Range
Rated motor

current
9999
0 to 12000r/min /
0 to 8000r/min ,
9999
100% 0 to 100%, 9999
0 to 12000r/min /
0 to 8000r/min ,
9999
100% 0 to 100%, 9999
0 to 12000r/min /
0 to 8000r/min ,
9999

Selection and protection of a motor

Pr. 9, Pr. 561
Pr.600 to Pr.604
Pr.71
Pr.9, Pr.71, Pr.80, Pr.81, Pr.83,
Pr.84, Pr.90, Pr.92, Pr.93, Pr.96,
Pr.672, Pr.702, Pr.706, Pr.707,
Pr.711, Pr.712, Pr.717, Pr.721,
Pr.724 to Pr.726, Pr.859
0 to 500A Set the rated motor current.
Set the level (resistance value) for PTC
0.5 to 30k
thermistor protection activates.
9999 PTC thermistor protection is inactive.
9999
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,
9999
Pr.601), (Pr.602, Pr.603), (Pr.604, Pr.9).
9999: Free thermal O/L relay invalid.
9999
Refer to Page
101
104
105
105
Description
101
4