Over Charging
Symptoms
> Compressor runs cold.
> High compressor discharge pressure.
> Excess frost on compressor suction line after evaporator.
> Sight glass shows full of refrigerant
Remedies
> Collect excess refrigerant gas to collecting bottle
Under Charging
> Low discharge pressure
> Large bubbles in the liquid sight glass
> Compressor delivery temperature high.
> Compressor continuously run without cut off or the cutoff interval will be too long
Remedies
> To charge the refrigerant until the bubbles disappear in the liquid sight glass and charging will correct the pressure gauge reading.
> To find out the leaky points by halide torch or soap solution or electronic leak detector.