im working on a 3 ton ruud rooftop package. last week I found the system iced up in cooling mode on about a 75 degree day. checked charge seemed good by superheat but my suction pressure was a little low right about 60-65 psig(r22 by the way). my head pressure was at 190. superheat was 12 degrees. so I then went into checking airflow, cleaned blower and ID coil. checked filter and return duct static. .3 of return static and .24 on supply. well got to that point and was sent on an emergency call that was more important. finally got back late this afternoon to see what I could find and in heating mode im seeing really high head pressure (275-300). compressor is going into relief to drop the pressure. true suction is running about 60-65 with around 14 degrees of superheat. then of course I got called back off again.(for those wondering what kind of company I work for...this unit just serves a warehouse and really isn't important to the owner and the store manager is in no rush to have it fixed if at all). well anyways I was thinking next blue moon when I get out there to check temp drop across drier and then if nothing there I will probably pull the charge and weigh back in what the nameplate calls for??? any suggestions?