Upon my arrival I went to the rooftop hatch with the manager on duty. At RTU#1 I found circuit #1 with the compressor not working because the wires have been pulled from the contactor because this circuit is completely flat of refrigerant. Circuit #2 is operating but is low on refrigerant as well. Both circuits need to be leak searched, the leaks fixed if possible, and then the remaining refrigerant recovered, both circuits pulled into <500 micron vacuum and charged with circuit #1: 328oz; circuit #2: 280oz of r407a refrigerant. This job will take most of, if not all day long. I completed a commercial work estimate and sent it to the office to finalize and reach out to the customer for approval ASAP.