split air conditioner issue

I have an issue with my new air conditioner, it’s a 1.75Hp inverter split Panasonic, I just installed a few weeks ago. I want to ask a question here before I call the insulation guy back.
Today it was very hot day so I ran it for a few hours on the coldest setting, I felt the air coming from the head unit, it was cold, but not really cold as it should be.
I inspected at the exposed 2 copper connections coming from the outdoor unit, it was very slightly wet and water had an oily texture.
Also, when its off, I can hear a very faint crackling sound coming from the area near the copper joins on the out door unit.
Is it leaking gas? Or does it need a few more runs before the air starts to get cold.


More...