Routine air conditioning refrigeration system inspection:

Refrigeration system pressure balance, low or high pressure measurement.

Current measurement, observe condensation and frost on gas and liquid valves, as well as the opening degrees of the two valves. Inspect the bending of the pipe extending through the wall, and whether the pipeline and wiring are extended between the interior and exterior.

(1) If it's a three-phase control, the phase sequence must be adjusted first.

(2) If there is no sound or indicator, or if the sound is abnormal, upon plugging in or turning on, be sure to check the power source. This includes the user's power source, the machine's power source, etc. Some power sources are provided from outside to inside, with transformers and wires outside.

(3) CPU operating conditions inspection. The operating conditions of the CPU include +5V, reset (resistor-capacitor 4.8V, integrated 3V), replacement of crystals, and checking for any leakage or short circuits in the peripheral circuit.

(4) Plug-in with or without beep, or receiver head failure.

Plug-in, with an audible alarm, protection after several seconds, check for open circuit, short circuit in the sensor, open circuit in pressure switches, temperature switches, etc.