Mitsubishi Electric FR-D720 K Series Instruction Manual page 109

(5) PTC thermistor protection (Pr. 561)
Inverter
U
V
W
10
2
PTC thermistor input connection
Thermistor
resistance
R2
Pr. 561
R1
Temperature-resistance
TN-ΔT
existing range
TN: Rated operational temperature
PTC thermistor characteristics
REMARKS
 When using terminal 2 as PTC thermistor input (Pr. 561
Also unavailable when using terminal 2 for PID control and Dancer control. When PID control and Dancer 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, Pr. 197 (output terminal function selection)
Motor
 Terminal 2 and terminal 10 are available for inputting of motor
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.
 Check the characteristics of the using PTC thermistor, and set
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
Thermistor curve
protection goes higher (protection works later), or lower
(protection works earlier).
 PTC thermistor resistance can be displayed in operation panel,
parameter unit (FR-PU07) (Refer to page 131.), or RS-485
communication (Refer to page 181.) when PTC thermistor
Thermistor
protection is active (Pr. 561  "9999").
temperature
TN+ΔT
TN
Refer to page 106.
Refer to page 151.
Refer to page 168.
Refer to page 213.
Refer to page 116.
Selection and protection of a motor

"9999"), terminal 2 is not available for analog frequency command.
Refer to page 122.
4
105