Midea V8 VRF Series Service Manual page 77

V8 VRF Indoor Units
6.1.29 d17 - Air inlet temperature of IDU is too high in cooling mode
Error display
The faulty IDU stops. Other IDUs of the same system: operate normally.
Error impact
ODU of the same system: operate normally.
If the air inlet temperature of the IDU is higher than the set value (See the operating temperature
Error trigger
range set out in the IDU Manual) for 5 min in cooling mode
Error recovery
Automatic recovery
Possible cause
See the Troubleshooting section.
Troubleshooting
Note:
1. The inlet air temperature sensor is commonly found in the fresh air IDUs (The sensor code is
defined as T0), and its resistance and temperature characteristics are similar to T1 - return air
temperature sensor. Please refer to the Table of Temperature Sensor Resistance Characteristics
listed in the Maintenance Manual to learn more about the sensor's features.
76
Digital display
Cause 1: Spot check the inlet air
temperature and measure the inlet air
temperature. If the point check result
is the same as the measured result
(error
measure for the unit. Otherwise, refer to
Cause 2: Remove the plug of the inlet air
temperature sensor from the main control
board of the IDU, measure its resistance
value, and compare it with the Table of
Sensor Resistance - Temperature
Characteristics (1). If the temperature that
d17
corresponds to the resistance value
deviates from the actual inlet air
temperature by more than 5° C, the sensor
Cause 3: The sensor body has come into
contact with a hot source, such as direct
sunlight or hot surface of a heat
exchanger, which causes the detected
value to be lower than the normal value
Cause 4: If the error cannot be cleared
after causes 1/2/3 have been eliminated,
the main control board of the IDU is
Panel, display box, and wired controller
1° C), it is a normal protection
cause 2/3/4
is damaged.
damaged
Display position
It is a normal
protection measure for
the IDU. When the
inlet air temperature is
lower than the set
value, the fault will be
cleared
Replace the inlet air
temperature sensor
Eliminate the
interference of
external hot source to
the sensor
Replace the main
control board of the
IDU