Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

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Parameters (H) Protective function parameter
FR-A800 5 - 311
●
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.
I002857E
Fig. 5-130: Thermistor protection level and detection time
NOTES When using terminal 2 for PTC thermistor input (Pr. 561 ≠ "9999"), the terminal 2 will not operate
as an analog frequency 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.
PTC thermistor resistance
The elapsed time count is cleared.
Pr. 561 setting
Pr. 1016
Time
ALM
E.PTC