How panasonic charging by superheat - GE Quiet-Aire Ductless Split System Air Conditioner AS1CD12AA0/AS0CD12AA0

You need to to determine the superheat and subcooling to check for the proper operation of your system when the compressor is running. I ran into a case just yesterday, the breaker kept tripping. Unit had the same readings as yours. This one had a subcooling of >25 degrees and 0 degrees superheat indicating unit was overcharged. I took an extra 8 pounds of r22 out of the system. During the investigation I also determined the filter/drier was blocking the refrigerant flow causing the technician to overcharge the unit. To check filter/drier performance all you need to do is measure the upstream and downstream temperature. The difference should be less than 2 degrees. This one was 7 degrees indicating it was metering flow. If your compressor stops operating before determining superheat and subcooling, you can get a professional tech to recover and weigh out the refrigerant in your system. You can look on the nameplate data on the side of the outside unit and see the ounces of refrigerant it is charged. If the compressor is operable go ahead and adjust charge by recovering the excess refrigerant into a recovery container for that refrigerant. Normal superheat and subcooling is normally around 10 - 15 degrees.
Hope this helps

Get a high velocity air filter, not a pleated one. Check air into evaporator section clean and passing air well. Next, check proper operation of blower motor and wheel. Next, check for proper charge by performing a superheat and subcool calculation. You will need a repairmant to check these. Superheat and subcool will tell you if your unit is properly charged and if you metering device is working properly. A typical superheat and subcooling value is around 10 to 15 degrees.

You will need to check the head pressure, condensing temperature, sub cooling and superheat to determine this, but yes sounds as so or restricted.

When technicians take an air conditioning course, one of the first things they learn is to use superheat to charge a fixed orifice air conditioning system.

Superheat is not hard to deal with, but the technician needs to take four good measurements.

To get the actual superheat, the technician measures suction line pressure and suction line temperature. When he reads suction line pressure, he reads the *F scale on his gauge. That's the boiling point of that refrigerant at that pressure. To get actual superheat, subtract the suction line boiling point temperature from the measured temperature of the suction line.

To read get the required superheat from the most common A/C manufacturer's superheat charts, the technician measures indoor "wet bulb" temperature and outdoor air temperature ("dry bulb"). Using these two temperatures the technician can look up the required superheat on most A/C manufacturers' superheat charts. Required superheat's can vary from 5 *F to over 45*F depending on the conditions (indoor wet bulb and out door dry bulb). The higher the load, the higher the required superheat.
The technician adds or subtracts refrigerant to decrease or increase the actual superheat to match the required superheat.

Superheat is the temperature difference between the boiling point of the refrigerant in the evaporator and the actual temperature of the refrigerant gas after the evaporator. It is the "extra" temperature (or temperature rise) the refrigerant picks up in the evaporator after it boils.

When charging the system, the technician adds as much refrigerant as he can. But if he adds too much (overcharge), he risks flooding the compressor with liquid refrigerant.

The biggest risk of flooding is under low load conditions: low outside temperatures and low indoor wet bulb temperatures. The refrigerant boils off late in the evaporator. To make sure the refrigerant is all boiled off before the end of the evaporator, the the A/C manufacturer's required superheat chart directs the technician to stop adding refrigerant when the suction line temperature gets down to within a few degrees of the boiling point inside the evaporator. The "few degrees" is the superheat. At low load conditions, the superheat is often specified as five or six degrees. It's a safety factor to make sure no liquid gets to the compressor.

At other load conditions, as determined by outdoor air and indoor wet bulb temperatures, the required superheat is given by a the superheat chart supplied by the A/C manufacturer. The higher the temperatures, the higher the load and the higher the required superheat.

Doing a superheat analysis is the best way to insure that an air conditioner has the proper charge.

Hello, in order to find if the sytem is operating correvtly you should measure the outdoor dry bulb temp and indoor wet bulb temps, this will givenyou a target superheat. Pressures will vary always use superheat. If superheat is higher than target add refrigerant if it is lower remove refrigerant.

Charging AC by superheat and subcool
First charging a unit by superheat, this is only for Acs with an orifice or capillary tube.
Optimum superheat is 12° to 15° at the compressor or suction line outside the unit.
Hook up your gages and put a thermometer on suction line (large line), start the AC. Measure the temperature of the suction line and read the pressure on your gages. Theres a temperature scale on your gages for R-22 or R-410A the needle will show you the pressure on the outer scale and if you follow it down to the R-22 or R-410a inner scale that is the saturation temperature for that refrigerant, (you can also use a temperature pressure chart), now read the thermometer, let’s say the suction temperature( the thermometer) is 67° and the saturation temperature (the gages or temp. press. Chart), is 55°, subtract the saturation temperature from the suction temperature, 67°- 55° = 12° superheat.
Charging by Subcooling, this is for Acs with a thermostatic expansion valve, it’s common to see a sight glass on the liquid line (on these units with a sight glass just clear it, when, indoor room is at approximate set point of the thermostat). Optimum sub cooling is 12° to 15° at the outdoor unit.
Hook up your gages and put a thermometer on liquid line (small line), start the AC. Measure the temperature of the liquid line and read the pressure on your gages. Theres a temperature scale on your gages for R-22 or R-410A the needle will show you the pressure on the outer scale and if you follow it down to the R-22 or R-410a inner scale that is the saturation temperature for that refrigerant,(you can also use a temperature pressure chart), now read the thermometer, let’s say the liquid temperature( the thermometer) is 100° and the saturation temperature (the gages or temp. press. Chart), is 114°, subtract the liquid temperature from the saturation temperature, 114°- 100° = 14° subcool.

take the temp and press reading as per manf. and cal actual superheat. what are the reading for amb, evap temp, pressures high low. Then adjust charge. you need to determine super heat based on dry bulb indoor and outside ambient the read suction line temp vs suction line pressure

Subcooling - The difference between the temperature of the Small copper line (Liquid Line) and the high-side (red) gauge temp on your manifold

Superheat - The difference between the temp. of the Suction line (Big copper) and the low side gauge (blue) temp

If it needs a charge the leak has to be found and fixed. If the leak has been fixed and you have a service valve on the low side. It should have a vacuum pulled on the system to remove all air and non-condensable gases from the system. Then you can charge the system : 1. by weight according to the name plate. 2. charge by superheat (temperature leaving the evaporator + 16°F) When using the superheat method to charge the higher the Ambient temperature the lower the superheat difference will be.