I am having issues with a Lennox 410a 7.5ton heatpump system. The system has a dual evap coil ran off a single ciruit compressor. My running pressure are way off with my low side at 60 and my high side at 310. I have checked the lineset for any restrictions and could not find any, I have also checked th expansion valve itself to make sure the orifice was clean. I am not a 100% that my valves are sized properly, there are 2 4ton expansion valves on this coil. Is this correct for a 7.5ton condenser and can a singal circuit compressor handle this dual coil??