Mitsubishi Electric 800 Series Instruction Manual page 322

PTC thermistor input (Pr.561, Pr.1016, E.PTC)
Inverter
Motor
U
V
W
10
2
PTC thermistor input
connection diagram
• 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
• 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.
Pr.561
setting
ALM
NOTE
• When using terminal 2 for PTC thermistor input (Pr.561
command terminal. The PID and dancer control functions assigned to the terminal 2 will be also disabled. Use Pr.133 PID
action set point to set the set point for the PID function.
• To input power to the PTC thermistor power supply, always use the terminal 10. Do not use any other terminals or an external
power supply. Otherwise, the PTC thermistor protection (E.PTC) does not operate properly.
• When E.PTC is activated, the alarm display, "External protection (AU terminal)", may appear on the parameter unit (FR-
PU07), but it is not a fault.
Thermistor resistance
R2
Pr.561
R1
Temperature - resistance
TN-DT
existing range
TN: Rated operating temperature
Example of PTC thermistor characteristics
PTC thermistor resistance
The elapsed time count is cleared.
(H) Protective function parameter
Thermistor curve
Thermistor temperature
TN+DT
TN
page 347.)
Time
Pr.1016
E.PTC
≠
"9999"), the terminal 2 will not operate as an analog frequency
321
PARAMETERS
5
GROUP
H