Selection and protection of a motor
PTC thermistor protection (Pr. 561)
PTC thermistor input connection
TN: Rated operational temperature
PTC thermistor characteristics
When using terminal 2 as PTC thermistor input (Pr. 561
Also, terminal 2 is not available for analog frequency command when using terminal 2 for PID control. When PID control is not
active (Pr. 128 PID action selection = "0"), terminal 4 functions as follows.
When Pr. 79 = "4" or in External operation mode ............... Terminal 4 is active whether AU signal is ON/OFF
When Pr. 79 = "3" ............................................................... Terminal 4 is active for frequency command when AU signal is ON
For the power supply terminal of PTC thermistor input, do not use power supply other than terminal 10 (external power supply,
etc). PTC thermistor does not work properly.
Parameters referred to
Pr. 71 Applied motor
Pr. 72 PWM frequency selection
Pr. 79 Operation mode selection
Pr. 128 PID action selection
Pr. 178 to Pr. 182 (input terminal function selection)
Pr. 190, Pr. 192 (output terminal function selection)
Terminal 2 and terminal 10 are available for inputting of motor
Check the characteristics of the using PTC thermistor, and set
PTC thermistor resistance can be displayed in operation panel,
Refer to page 123
Refer to page 181
Refer to page 200
Refer to page 250
Refer to page 134
Refer to page 140
built-in PTC thermistor output. When the PTC thermistor input
reaches to the resistance value set in Pr. 561 PTC thermistor
protection level, inverter outputs PTC thermistor operation error
signal (E.PTC) and trips.
the resistance value within a protection providing temperature
TN, just around the center of R1 and R2 in a left figure. If the Pr.
561 setting is closer to R1 or R2, the working temperature of
protection goes higher (protection works later), or lower
(protection works earlier).
parameter unit (FR-PU07) (Refer to page 152), or RS-485
communication (Refer to page 218) when PTC thermistor
protection is active (Pr. 561 "9999").
"9999"), terminal 2 is not available for analog frequency command.