A/C Compressor Only Turning on and Off

Turbo98

My central air conditioning unit is 3 years old and doesn't see a huge amount of run time. I don't keep it that cool in the house. The A coil in the furnace is basically new. When it starts to get hot in the afternoon and the unit starts running more and more, the compressor will shut off. The fan on the outside unit continues to run but starts blowing non-heated air. The furnace blower keeps running and now doesn't blow cool air. If the t-stat is left alone, everything but the compressor will continue to run until it turns back on at some point--then it will starts cooling again. Or if I shut if off and wait 1/2 hour or whatever, it will start cooling again. It's almost like if it gets to a certain temperature, it shuts itself off. Nothing is frozen.

I'm not an a/c tech person but it seems that maybe there is a simple limit type switch that will turn the compressor off if the pressure is too high or too low. The refrigerant pressure has been checked and is normal. But if that switch is bad, I suppose this could cause it to shut off even when the pressure is in spec, correct? Do these switches often go bad? It seems like something is getting hot causing it to shut off. Do most central a/c units have a switch like this? Or what else could cause this?

Thanks for the help.

hvac122

What kind of unit is it. Is the outdoor coil dirty? May be going off on internal overload. What were the specs when charge was checked?

Turbo98

All I know so far is that the pressure was around 80 when it was very hot out and around 70 right after the unit turned on in the morning. The coils aren't dirty. I'll check on the brand and post it.
Thanks.

Jacques

I would call the warrantor [installer] sounds like comp going bad or weak overload. assuming the comp is getting proper air flow... the only thing that -just- turns off comp is it's overload [heat or current out of limits]... a compenent a/c guy should be able to tell right away what the prob is. turn it on ahead of time.