R134a overload on Kia Rio

[smartever]

Hello,

I have a DOOWON compressor on which it's indicated high side 36kg/cm2, low side 17kg/cm2.

To load r134a on my car which did not contain it at all, a service provider put 550g. Two days later, seeing that it cooled very little, the provider increased to 650g, result: slight improvement. Less than 1 hour after I was informed that the standard on my vehicle was 420g, I come back immediately to make a long emptying and put 420g in total, which gave a very good result.

Should I worry that there was a 30% overload (additional 130g in total that stayed 2 days while A/C was used), followed by another 55% overload (additional 230g in total that stayed 1 hour while A/C was used)? If so, for which parts to worry?

Many thanks for your answer and help.

[Cornbinder89]

I wouldn't worry about the overcharge. The system most likely has a relief valve if the pressure got too high. Over pressure is the only issue that I can see with that amount of overcharge. Two things that will do damage, liquid reaching the compressor and excessive pressure. Most systems have a relief to vent excessive pressure that is high enough to do damage.
Too much refrigerant causes liquid to back up into the condenser, and raise the condensing temp of the refrigerant. This is why you saw the system performance drop off with the extra refrigerant.
How high the pressure gets is dependent on the temperature of air passing over the condenser. In very hot climates it may go as high (375 psi/ 25.855 bar). Most relief pop off at 425 psi or more.

[smartever]

Many thanks for your help. Please note that the outside ambient temperature was between about 73 fahrenheit degrees and 93 fahrenheit degress.

You explain: "over pressure is the only issue that I can see with that amount of overcharge" but in the other hand you say: "too much refrigerant causes liquid to back up into the condenser, and raise the condensing temp of the refrigerant. This is why you saw the system performance drop off". So in my case, did I have only acceptable excessive pressure OR excessive pressure + liquid reaching the compressor?

In the second case what damage can liquid back up cause to the compressor?

Thanks in advance.

[Cornbinder89]

For liquid refrigerant to make it back to the compressor, there would have to be way more in the system than you ever had. You know because it would lock the compressor and burn the belt. You can't compress a liquid and the compressor can't expel it through the valves as fast as the pistons are moving, so it stops it from turning.
There is no damage caused by liquid backing up in the condenser, in fact it happens all the time if you run the A/C on cool days, The full surface area of the condenser is not needed, and the gas rapidly turns to liquid in the condenser.

[smartever]

Many thanks for your technical advice. So for someone like me who does not know too much about it technically: I have to understand that there is absolutely nothing to fear and that this overload has not tired the compressor. Correct?

[Cornbinder89]

Yes, nothing to fear.
Please when responding use the dialog box below the post you are responding too. When you just make a comment, it doesn't show up as a "new post" on the thread and may go un noticed for days. New posts are highlighted in the main menu and I'll see them whenever I log on. If you want to "reference a piacular post you can use the "quote" option to include the whole post or only part of it into your post.
Thanks

[smartever]

If you want to "reference a piacular post you can use the "quote" option to include the whole post or only part of it into your post.
Thanks

Many thanks for your great help. I found this forum very interesting and helpful. Sincerely.