In an automobile, there is a pressure switch that acts as a fail safe to
> prevent compressor damage if too much or too little refridgerant. Does a
> home air conditioner have the same fail safe switch?
>
> Logic dictates that it does, but I've never even had my home system charged,
> so I've never looked inside to see what's in there. I have a friend that I
> do handyman work for, and he called me to say that his AC does not work. He
> sets the tstat and the forced air unit (huge fan) comes on, but the
> compressor outside in the yard does not come on. My theory is that he needs
> to have the system charged because the low pressure switch is detecting no
> "freon" (where freon means whatever they used in his system). I have no
> intention of performing the service, I just wanted validation that the house
> has the same basic components as the automotive system, specifically a low
> pressure switch. I will look at the system to be sure it hasn't blwon a
> breaker, and that sort of thing, but I haven't got the equipment to do > anything else.
>
>
That problem happened to my home AC system a little while back. I found an earwig beetle had gotten caught between the contacts of the big relay in there that's energized when AC is called for. It wasn't quite enough just to get the body out - - had to use some emery paper on the contacts to get them clean again.