Need a/c assistance

[Harry L.]

My psi on the low side gage reads 20 and the high side gage reads 200 psi, at 1700rpms, at 80 degrees. The receiver drier shows no bubbles, and inside vent temperature are high 30s. Would I be able to raise the low side psi with the spring adjustment on the STV valve? I do not know how to raise the low side to 29 psi, any suggestions? Dutch Long

[William F.]

Re: Need a/c assistance

Why change it ? It's blowing cold.

[Joseph S.]

Re: Need a/c assistance

Troubleshooting guides for low suction pressure point at suction side restriction. Expansion valve (probable), evaporator or line restriction. I assume it is an R12 refrigerant system. Joe

[Harry L.]

Re: Need a/c assistance

Yes, it is an R-12 system. Do you know the procedure for finding superheat and sub-cooling data for determining how this system is running?

[Joseph S.]

Re: Need a/c assistance

Try this website- walks you through the process:

https://www.sanden.com/objects/3_-_Troubleshooting_-_Web_01.pdf

Depending on you normal high side pressure at 80 degrees the low suction pressure may as simple as low refrigerant charge. Joe

[Harry L.]