【 Weak current College 】 refrigeration system failure symptoms (3)

6. evaporator unit of temperature variation on the impact of the refrigeration system
(1) thermostatic expansion valve exterior temperature (including the electronic expansion valve) under normal circumstances, the second part of the expansion valve body is very cool, and dew, refrigerant flow sounds very boring. Not normally, a comparison between the valve body is cold, surface dew more, even the frosting, refrigerant flowing sound larger (gas flows). The reason for this is the filter blockage, or power box refrigerant leakage valve hole close is blocked.
(2) temperature capillary in normal situations, capillary hair cool and knot have dew, a liquid flow of sound. Not normally, one is very cool, but also the surface condensation, but mobile sound a sound, is gas flow, the reason for this is lack of refrigerant; second, the surface is not cool, no condensation, no mobile voice, filter clogging or capillary clogging.
(3) evaporator temperature in normal circumstances, the external surface of the evaporator is very cold, the dew condensation drips continuously, and out of the air temperature is large, usually Δ t may 12 ~ 14OC. abnormal situations, the evaporator surface not too cold, dew, or no dew, can hear the sound of refrigerant flow in and out loud, small air temperature difference. The reason for this is the amount of the refrigerant is insufficient, or expansion valve opening.
7. the influence of ambient temperature
(1) outdoor unit of environment temperature requirements stipulated by national standards, outdoor unit in ambient temperature is the temperature below 35OC, air-conditioning unit should ensure that properly, and to achieve the objective of the product nameplate cooling capacity, and other indicators. When the ambient temperature at 35 ~ 43OC, the air conditioning unit can run, but cannot guarantee its CR licence the marked cooling capacity, it is already in full load operation, this is the condensation temperature, pressure, exhaust temperature is very high, to a large indoor thermal, electrical protection devices is possible action, cut off the power to stop running. When the outdoor air temperature exceeds 43OC, the air conditioning unit is run, overload can cause electrical protection devices, power off, stop running.
(2) the requirements of the indoor air conditioning temperature thermostat indoor normal maximum values should not exceed 30OC. If more than 30OC temperature, the air conditioning unit is possible in the overload condition run, refrigeration system condensing temperature and exhaust temperature will rise, or may cause electrical protection devices, power off, run the air conditioning unit of life.
(3) heat pump system with single cold, the heat pump operates correctly, check the reversing valve. Directional control valve, can be heard more loudly gas flows acoustic and electromagnetic valve thimble of impact sound (EMF suction valve heart), when the solenoid valve in the reversal process cannot hear these two sound, the solenoid valve may fail.