Fujitsu AUUH18LUAS - Compressor Temperature Protection; Indoor Unit Fan Motor over Temperature Protection

8-4. Indoor unit fan motor over temperature protection
The fan motor over temperature protection activates after two judgments when fulfilling any of the
following conditions.
• Detected that the rotation number of the fan motor stays 200 rpm or less for 10 seconds after 90
seconds from the fan operation started.
• IPM trip protection activates.
• Current overload protection activates.
At first, the function determines if any of the above conditions apply (First judgment). If any of the
above conditions apply after the first judgment, the function will make the second judgment after 6
minutes. If any of the above conditions still apply in the second judgment, fan motor over tempera-
ture protection activates.
• Protection details
The function lowers the static pressure by 20 Pa. If the problem is not resolved even at the mini-
mum static pressure, the unit operates as follows.
– Fan motor error will be displayed if the fan motor speed stays 200 rpm or less for 10 seconds
after 90 seconds from the fan operation started.
– The fan stops 40 seconds after the activation of the IPM trip protection.
– The fan stops 50 seconds after the activation of the current overload protection.
8-5. Compressor temperature protection
→hen the compressor temperature sensor detects higher than the trigger condition below, the com-
pressor is stopped. →hen the compressor temperature sensor detects the release condition, the pro-
tection is released.
Trigger condition 226.4°F (108°C)
Release condition
176.0°F (80°C)
(3 minutes after compressor stop)
8-6. High pressure protection (for 24/30/36 model)
Trigger condition
Pressure switch: Off (Open: Higher than 4.2 MPa)
Compressor stop
Release condition
Pressure switch: On (Close: Lower than 3.2 MPa)
(3 minutes after compressor stop)
Compressor restart
8-7. Low outdoor temperature protection
→hen the outdoor temperature sensor detects lower than the trigger condition below, the compres-
sor is stopped.
Operation mode Cooling/Dry
18 model
Trigger condition 5°F (-15°C)
Release condition 14°F (-10°C)
24/30/36 model
Trigger condition -13°F (-25°C)
Release condition -4°F (-20°C)
8-4. Indoor unit fan motor over temperature protection - (04-40) - 8. Various protections
CONTROL AND FUNCTIONS CONTROL AND FUNCTIONS