Mitsubishi Electric FR-A820-00046 Instruction Manual page 512

(H) Protective function parameter
PTC thermistor input (Pr. 561, Pr. 1016, E.PTC)
Fig. 5-129:
● Output from the PTC thermistor, which is built into the motor, can be input to the terminals 2 and
10. If the input from the PTC thermistor reaches the resistor value set in Pr. 561 "PTC thermistor
protection level", the PTC thermistor operation (E.PTC) shuts off the inverter output.
● Confirm the characteristic of the PTC thermistor to be used, and set the resistance for Pr. 561
around the center of the R1 and R2 values shown on the figure above so that it does not deviate
from the protective function activating temperature TN. If the Pr. 561 setting becomes too close
to R1 or R2, the protective function activating temperature may be too hot (protection is delayed),
or too cold (too much protection).
● When the PTC thermistor protection is enabled (Pr. 561 ≠ "9999"), the resistance value for the PTC
thermistor can be displayed on the operation panel or via RS-485 communication. (Refer to page
5-344.)
5 - 310
Inverter
Motor
U
V
W
10
2
Thermistor resistance
Pr. 561
Temperature – resistance
existing range
Example of PTC thermistor characteristics
Fig. 5-128:
PTC thermistor input connection diagram
Thermistor curve
R2
R1
TN-DT TN+DT
TN
TN: Rated operating temperature
Thermistor temperature
Parameters
I002584E
I002585E