Mitsubishi Electric FR-F820-00046, Instruction Manual

Page: 329 / 940

Parameters (H) Protective function parameter
FR-F800 5 - 157
PTC thermistor input (Pr. 561, Pr. 1016, E.PTC)
●
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
5-198.)
●
When the PTC thermistor protection level setting is used, use Pr. 1016 "PTC thermistor protection
detection time" to set the time from when the resistance of the PTC thermistor reaches the
protection level until the protective function (E.PTC) is activated.
If the resistance of the PTC thermistor falls below the protection level within the protection
detection time, the elapsed time count is cleared.
Fig. 5-51:
PTC thermistor input connection diagram
I002584E
I002585E
Fig. 5-52: Example of PTC thermistor characteristics
U
V
W
10
2
Motor
Inverter
R2
R1
TN
TN+DT TN-DT
Thermistor resistance
Thermistor curve
Thermistor temperature
TN: Rated operating temperature
Temperature – resistance
existing range
Pr. 561