I have cellar Cooling System running on R407c. The Compressor (Copeland Scroll) is low on oil. I know I need an Ester oil But which one? I took note where the compressor says POE but the only other details were the amounts it needs in 0z and L. Also where should the oil level sit on the sight glass? I want to avoid taking the old oil out and re-charging if I can.

Thanks in advance guy's!!