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80415F_MSW_GFX4-IR_05-2019_ENG
Overheat alarm
The controller has a temperature sensor for the internal heatsink. The temperature value of the heatsink is in variable
INPTC; the over_heat alarm trips when the temperature exceeds 85°C.
This condition may be caused by obstructed air vents or by a blocked cooling fan.
The over-heat alarm is cancelled when the heat sink temperature falls below the value of 75°C.
With the over_heat alarm on, the control disables control outputs OUT 1, OUT 2, OUT 3 and OUT 4.
It’s provided the intervention of the alarm also for speed increase (derivative) of the temperature INPTC greater than
7°C in 12 seconds.
There is another maximum temperature protection that disables the hardware for the SSR controls.
655
R
INPTC
SSR temperature
°C
675
R
INPTC_DER
derivative of temperature SSR
°C/12sec