This can be HARD ON equipment. I once was called to a "no cooling" call to a building I had never been to, an independent doctor's office. I wasn't sure what I was up against because we did not install these, and I'd never been there previously. When I parked, I could see the line of about 6 split units (there were more package rooftops on the second story) so I took a quick look at them. A couple were not running, 2 were running, and a quick "feel" of the tubing came up with reasonable "feel" AKA warm liquid lines and cold sweaty suction.
The remaining one had an OVERLY WARM suction line!!! WTF??? Is this a HEAT PUMP?? A quick look through the fan nope, no reversing valve, WTF??
So I went up and talked to the office people, they had replaced the stat with some import programmable thing, probably switched with SCR instead of relays. IT HAD LOCKED THE HEAT ON and the stat was calling for cooling so it had the furnace and the AC running same time. The furnace, below the AC, was pumping heat like mad into the EVAP!!!
They may have shortened the compressor life by a few years.