R410A Question

[toyo066]

I have a question on this... I am trying to figure out the temps and all that with R410.... We had a mini split to install today which was a R410 system... On these units you have NO liquid side to put your gauges on... At 80 degrees we had 55 psig and the temp at the air handler on the copper line set was 45.3 degrees.... what is the superheat for this and how do you get the correct spec on the freon.... I know that it has to be about a 10 degree diff here but I am lost when you dont have the liquid side to work with....
I have been in A/C field for almost 5 years now and I am just now working with the R410A... I use to push it off on other techs but as the times change I guess it is time to buckle down with it....

[catmanacman]

i find it best to weigh in the charge on this type unit

[tinknocker service tech]

I have a question on this... I am trying to figure out the temps and all that with R410.... We had a mini split to install today which was a R410 system... On these units you have NO liquid side to put your gauges on... At 80 degrees we had 55 psig and the temp at the air handler on the copper line set was 45.3 degrees.... what is the superheat for this and how do you get the correct spec on the freon.... I know that it has to be about a 10 degree diff here but I am lost when you dont have the liquid side to work with....
I have been in A/C field for almost 5 years now and I am just now working with the R410A... I use to push it off on other techs but as the times change I guess it is time to buckle down with it....

with these units the charge is very cridecal
find out what lenth and size line set you have a weigh it in
the directions that came with it give exact details on charging and weighing it in.

it is so easy to over charge these things 410-a or 22 doesn't matter weigh it in

[jrbenny]

You can't charge by subcooling or superheat on those systems. You must weigh the charge.

[toyo066]

I have heard a few different things from other tech's but they dont have the experience with the 410... However, if you do it by the scale that is cool when it is empty, but what took place was we went to do the flare on it and it leaked out, put a vac on it and it held. However, for whatever reason it leaked upon releasing the 410 into the system... SO therefore, we did not know how much we lost... I over charge her and she popped on me after 20 seconds or so... I had the suction side to 150 = 55 on the psig for the 410 which held ok and was cooling just nicely... Hate to do that without getting the right specs but it had to be done for now until I can really understand the 410 temps.... Had a cold one in the hand..... Felt good to me!!! NOT!

[FireAir7215]

Recovery the refrigerant out of the system, install new service port on liquid line. Pull vaccum and etc, charge up the exact weight what nameplate said or do the pressure temperture.

[hvaclogic]

Isn't there a liquid line service valve inside the unit next to the compresor?