P7- Indoor Anti-Freeze Protection During Cooling - Toyotomi KURO Mini Service Manual

P7- Indoor anti-freeze protection during cooling

Error
phenomenon
Explanation of
error
Tools required
for inspection
Frequent
problematic part
Inspection
procedure and
key points
Error code
LED light signal of
external panel
Cause: When the indoor and outdoor temperatures are too low, or the
indoor unit is dirty, the evaporation temperature is lower than 0 °C
during cooling, and will reporte indoor anti-freeze protection.
Inspection path: internal coil sensor → the main internal control
panel → filter → indoor motor →evaporator→ refrigerant
Multimeter, 20KΩ standard internal coil sensor（25℃）
Indoor evaporator coil temperature sensor is abnormal, Filter is dirty,
Indoor motor speed is out of control, too little refrigerant
1. Perceive the temperature of the thick connecting pipe or evaporator
by hand. If there is no obvious hot touch (<60°C), the internal coil
sensor is abnormal, replace the internal coil sensor, otherwise, continue
to check according to the following steps;
2. Check whether the indoor filter is dirty or not. If the filter is dirty,
clean the filter. Otherwise, follow the steps below to continue
troubleshooting.
3. Check if the indoor fan speed is too slow. If the speed is abnormal,
replace the motor or the indoor controller. Otherwise, follow the steps
below to continue troubleshooting.
4. The temperature of the two outlets of the evaporator is sensed by
hand to determine whether there is a possibility that one of the flow
paths is welded. If there is a welding condition, replace the evaporator,
otherwise continue to check according to the following steps;
5. Excessive refrigerant may also cause P6 error, empty all refrigerants,
and use the electronic scale to add a sufficient amount of refrigerant;
P7
LED1
LED2
LED3
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