High pressure

Hello, this is my first time ever posting so I really don't know how it works I will appreciate some advice on an issue that I have recently experienced I been an HVAC technician for the last 6 year I have a York package unit 30 ton 407-C with two circuits both going off on high pressure I have try the basics both fans are running coils are clean so are the filters I assumed that I wasn't the first one that has worked on it so somebody might have added more refrigerant so I thought it could be overcharged so I recovered all the refrigerant triple vacuum the unit and nitrogen in between to clear any non condensables then I charged with virgin 407 each circuit takes 17.6 lbs and I put 15 just to make sure I didn't overcharged it after all this both compressors keep tripping on high pressure so my question will be if I'm missing something? Is there any other things that I could do if you gentlemen have an idea you would like to share it will be highly appreciated I'm pretty much inexperienced compare to a lot of you guys I'm just humbly eager to learn how can I fix this issue thank you in advance for your help and support