Hi,

I am new in the refrigeration field, I am still learning.

One of these days, I was trying to charge a split air conditioner which works with R410a. I was charging it in the low pressure side because it didn't have a service valve in the high side. Before, I had read that it is recommendable to charge R410a in the high pressure side because the refrigerant should enter into the system in its liquid form. But, as I said before, this system didn't have service valve on the high side. So, I charged it in the low side and slowly (to avoid liquid refrigerant in the compressor). To do so, I opened the cilinder valve copletely and I was opening (just a little) and closing the manifold's low pressure valve many times, In this way , I expected, the refrigerant would enter slowly into the system. But after some opening-closing cicles, the refrigerant and oil began to leak through the manifold joints in the low side. I quickly closed the valve in the refrigerant cylinder, and the leakage didn't stop so I disconnect the manifold from the service valve in the air conditioner. While the "gas" was going out through the manifold, some ice formed near the leakage joints. I thought the manifold got damaged, but to be sure, I decided to connect it againt to the service valve in the air conditioner, but it worked well this time: there wasn't any leakage.

It seems that the manifold doesn't work properly under low temperatures, at least this was my conclusion.

Could anybody explain what happened? Why did the the refrigerant and oil begint to go out through the manifold while I was charging? Why didn't it happen the second time I connected the manifold?