Routine inspection of air conditioning refrigeration system:

Balancing pressure in the refrigeration system, low or high pressure measurement.

Current measurement; observe condensation and frost on gas and liquid valves, the opening degrees of both valves. Check the bending of the pipes passing through the wall, whether the piping and wires are extended between the inside and outside.

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

(2) If there is no sound or indicator display upon plugging in or turning on, or if the sound is abnormal, always 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 the inside, which include transformers and wires.

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

(4) Plugged in with beeping, no beeping, or receiver head failure.

(5) Plug-in, with a sound, protection after several seconds; check for open circuits, short circuits in sensors, and open circuits in pressure switches, temperature switches, etc.