HOW DO YOU CHARGE R404 A SYSTEMS REFRIGERATION

I can explain how to do it but you will need a F-Gas certified professional refrigeration technician to do this job.

If you unscrew the 4 screws to the compressor closet, you will see a copper stump on the side of the compressor, that stump used to have an access valve that allows refrigerant to be measured into the refrigeration system. For gas to be reapplied a technician will have to re-braze a valve onto that stump in order to recharge refrigerant into the system.

as long as you recovered the charge, pulled a vacuum, changed the filter/dryer, and added the correct amount of refrigerant as a liquid, you should be good to go.

If refrigerant was added (freon), then one of 2 things may be going on. First, he could have overcharged the system. Too much freon. Second, it was low on freon. If it was low, then look for the leak as it will only get low again. The refrigeration system is a closed, sealed system.
When temp rises rapidly, it could be that one of the doors are not seal well. I have only had one unit in my years of experience where the unit would gain enough temp to cycle the unit on in about 2 minutes. Never was able to find the answer but the unit never failed and no food was ever lost.

Hi,

Yes, it sounds like you are low in charge...

Here is a tip that I wrote about how to add refrigerant to a air conditioner or cooling system

How to add Freon to a Air Conditioner or Refrigeration System

heatman101

Good day,
Yes, the new high efficiency units tend to run a lot compared to older models. That in fact is not a bad thing, since the compressor has to cycle on and off fewer times per day, and starting and stopping are what create wear and tear on refrigeration equipment. Actually you pay less because of the much smaller compressor that uses less power.

However, keep an eye on it. If it gets continually worse going forward, call for service. Hopefully Frigidaire has solved it's problems but was known to develop internal restrictions in the refrigeration system causing that problem to the point it runs continuously and fails to cool properly.
If the machine is under 5 years of age it would be corrected free of charge.

why yes there is. Generally speaking, the head pressure should be around the "ambient +30" rule.
That is, measure the entering air temp to the condenser, say 75 degrees. Now add 30 to that and get 105 degrees. Look at a P/T chart and see what the pressure is for that temp which is about 253 for R-404-A.
The evap on a freezer leads the load so, as a general rule, the evap temp is going to be around minus 10 degrees to get a 0 degree box. Coolers are different. So, the pressure for a minus 10 evap is around 25 or so. But the unit has to be close to operating temp. If the box is warm, naturally the pressure is higher. And what influences the pressure is whether or not it's a TXV or a cap tube system.
If a TXV and no receiver, charge by subcooling. If a receiver, fill by sight glass. If Cap tube, charge by superheat.
Hope that answers your question.

This one you have to get access to the refrigeration system to see what operating pressure you have to determine if there is enough freon charge to freeze. you need a tap valve and refrigeration gauges.

Depends on what kind of refrigerant its works, if is an old unit probably is charged with R12 or R22 newer ones work with R404 ;for R12 presures should be around 20psi on the low side and 160 on the high side ,for R22 about 60 and 250 and for R404 50 and 350 ;you have to look at the condensing unit tag to find out what type of freon its uses ,or look at the expansion valve at the evaporator coil.

Beverage air used R134a almost exclusively on refrigerators. The process is similiar to ac systems. You should weigh the charge in as per the data plate. Be precise as over or under charge can dramitically affect the performance of the unit. Hope this helps

most units are on a timed defrost that occurs at different times so finding the exact time will be hard but defrost times are about 30 minutes. from the pressures you posted I'm thinking that the condenser fan is not running or the condenser itself is plugged up with dust. (i'm not very familiar with r404 but for most other refrigerants the hi side pressure is really hi). if its still in warranty you would be better off to call your service company after your sure the condenser itself is clean to prevent a charge for impproper maintanence. thanks peyton