a/c need help

[kimspringfield]

hi

i have an old R22 A/c,

i have a charging connnection after the expansion valve and b4 the evap. I also have a sight glass after the condenser.

The problem is that is does not seem to be getting too cold. I have a thermocuple on the outside of the tube, it starts around 23C and drops to 17C

Also, after some time, the compressor shuts off b/c some swtich kicks in. Load is too much ( I think)

Plz help me

This is what i do, i vaccum it. Then add charge using the vapor port. Sometimes when I then run it, i add more charge.

IS there anyhting wrong

[Mickvee]

Hi
It looks to m you may have a problem with the expansion valve, but I would check the sight glass to see if you can see refrigerant flow, when the compressor starts and stops.
It may be cutting out because of low pressure in the suction line. The only connecting valve I have seen close to the expansion valve is for measuring the super heat across the evaporator.