Performed a 4 system maintenance checking heating and cooling. Checked all electrical and mechanical components, amp draws and capacitors. Checked filters and manager mentioned that one of the units is making a loud noise and it’s not cooling. Found that RTU2 has a bad 3-phase disconnect that is not allowing power to pass through. Along with a bad contactor for compressor 1. System is not getting the power it needs to run. Found that in RTU 3 the contactor needs to be changed out as well. Sent estimate over to Kelly for repairs.