Carrier rooftop model 50TJ-016-520YA Runs a while and trips internal OL's. Suction 70 psi. Head 285 - 290. R22. Didn't have a thermometer up there, but suction line is getting pretty cool, not cold. All three cond fans running good. Not tripping low or hi press switches. Semi hermetic. Thanks for any ideas. It was getting late. I'll get back on it tomorrow. The first time it did it I reset system and it ran for a day. Now it is tripping within 10 - 15 minutes. It seems to be doing it after noon when it gets hot in the day ???