Hello,
Having some trouble with a 25 ton AC system. After a few minutes of running the compressor starts cycling very quickly - on and off every
3 seconds or so. When it's doing this the supply pressure guage show a fairly steady 130 psi. The suction pressure guage rises to about 40 psi when the compressor is running and drops to about 20 psi when stopped. It's not HP cut out, the condenser is getting plenty of cooling water. It's not motor overload either. What's going on? Expansion valve not opening properly?
Any suggestions appreciated...