TCL TCA-18HRA/DVO, Техническое руководство, Страница: 80 / 113

DC Inverter Air
(1) The design load for the air‐conditioner is not enough;
(2) Improper installation results in no wind from the air conditioner;
(3) The return air design of air conditioner is unreasonable, resulting in an unreasonable air flow in the room
and uneven room temperature;
If the AC cooling effect is indeed poor after the inspection, there may be the following reasons:
A. The running frequency of inverter compressor is wrong and its frequency is lower than the target frequency.
The factors restricting the running frequency of inverter compressor include:
The exhaust temperature of outdoor unit is too high, the voltage is too high or too low, the current is too big,
and outdoor ambient temperature;
B. The refrigerant amount of the outdoor unit is too little or too much
Inspection and Treatment: it can be judged by testing the system temperature and pressure.
The normal temperature and pressure of the system are as follows:
Measuring point Normal Normal Max. cooling Max. heating
Cooling heating
Exhaust Temperature(
℃
) 85‐90 70‐80
＜
115
＜
110
Return air Temperature(
℃
) 8‐12 ‐3‐3 ‐‐ ‐‐
Cooling Temperature (
℃
) 48‐52 ‐1‐1 <65 ‐‐
Heating Temperature (
℃
)
7‐9 42‐50 ‐‐ <60
Super‐cooling/superheating 5‐10 5‐10 ‐‐ ‐‐
degree (
℃
)
Exhaust pressure (Pa) 1.7‐1.9 1.7‐1.9 2.3‐2.5 2.3‐2.5
Return air pressure (Pa) 0.45‐0.6 0.4‐0.5
＜
0.7
＜
0.7
When the refrigerant amount is too little, its symptom is as follows: exhaust air and return air temperature is
higher, LV pressure and HV pressure is lower;
When the refrigerant amount of outdoor unit is too much, its symptom is as follows: exhaust air and return air
temperature is lower, LV pressure and HV pressure is higher;
C. Air Channeling of Compressor or Four‐way Valve
Common phenomena: poor cooling effect, higher LV pressure and lower HV pressure
Distinction: when there is an air channeling in four‐way valve, the noise of four‐way valve is bigger, and the
temperature difference is very big while testing one position and four positions of four‐way valve, and there are
many tested temperatures far beyond the normal temperature (normal temperature difference is 3°or so);
D. Poor Heat Exchange of Outdoor Unit (Installation space of outdoor unit is smaller and the condenser is too
dirt)
Phenomena: higher exhaust air and return air temperature; higher LV pressure and HV pressure.
E. System is Blocked
Phenomena: higher exhaust air and return air temperature; lower LV pressure and higher HV pressure.
G. Throttle Member failed
The electronic expansion valve of outdoor unit cannot be opened.
There may be the following reasons: the electronic expansion valve or the coil is damaged, the electronic
expansion valve assembly of electric control panel drive is damaged;
3) The system can be started for running but it is usually subject to abnormal protective shutdown during the
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