Sissy Air Conditioning

[Rob]

Thad makes some very valid points and there are a few more to go with them:

In a new system such as yours that is untested, one needs to ensure there is enough lubricating oil within the system. A very good ratio of PAG, or ester oil to refrigerant capacity is seven ounces of oil per pound of refrigerant in the system. Too little oil and the compressor does not last. Typically the aftermarket suppliers are using either a Sanden compressor, or a variant of the type. These have a sump with a plug in the side of the body. With the compressor level, remove the plug, and fill the sump with oil to the bottom of the threads in the body and replace the plug. Remove the plugs in the suction and discharge ports and pour about 1/2 ounce oil in each and turn the compressor clutch slowly over by hand. When you have made about six revolutions of the clutch, install the plugs back into the compressor ports. Now either install onto the engine or place in an out of the way place so you can lose it............

After you mount your condensor, evaporator and ancillary equipment and just before running the linesets, pour about 2 ounces of oil in the condensor, and evaporator with the balance in the receiver/dryer, or accumulator. Figuring about a 2 pound refrigerant capacity system you will now have between 12, and 14 ounces total oil in the system and this is enough to get started. I then install the lineset(s), (lubricate any "O" rings with refrigerant oil) and tighten to proper torque. Use ample clamp to secure the lines from the enging mounted compressor to the evaporator and condensor also.

As Thad stated pull the system into a deep vacume in excess of 29.75 inches and let the system dwell with the vacume pump running at least two hours. One step further I take is to introduce 50 psi of nitrogen into the system and allow it to set for at least 30 minutes to extract any remnants of moisture check for leaks/integrity. After passing these tests, the system is again pulled into a vacume for a couple minutes. I then introduce liquid refrigerant into the high side charge port while the refrigerant bottle sets on a calibrated scale. When there has been one pound of liquid refrigerant introduced into the system, I shut the flow off. This is allowed to stabilize and "flash", or evaporate into a gas within the system so the compressor is not "slugged" upon startup. About two minutes is enough but if the system is started immediately and liquid refrigerant hits the compressor, it's bye bye time for the valves in the compressor.

At this time you can engage the system and begin to introduce more refrigerant in the form of gas into the low side, (suction port) of the compressor. Dependent upon the ambient temperature of the air will dictate your compressor discharge pressure but stay below 300 psi at all times. Most R-134 systems will not let you exceed 350 psi as a safety precaution and will shut the compressor down by releasing the clutch. With the windows closed in the cabin keep charging and looking for about a 33-35 degree evaporator temperature as indicated on your suction, or low side gauge that is blue in color. Using R-134 refrigerant with an ambient temperature of 90 degrees F, you should be about 255 psi to 270 psi dependent on humidity level. Don't overcharge the system as efficiency degrades quickly and loss of cooling is the result. Watch closely as you near the 33 degree temperature because I've seen several times a guy walk away and introduce more refrigerant than needed with less than desirable results.

Most of Red Dot's roof mount units have a built in fan to pull air across the roof mounted condensor so you will not need a fan. If you use a front of radiator mount condensor coil you would need to place a box fan to blow cooling air across the coil.

Keep note of how much refrigerant has been introduced into the system via the scale. When your low side suction gauge reads about 30 degrees run a calculation of how much oil the system is still short assuming the seven ounces of oil to refrigerant ratio and continue to introduce the needed amount of oil. The refrigerant will circulate it within the system.

Rob

[randyp]

Thad makes some very valid points and there are a few more to go with them:

In a new system such as yours that is untested, one needs to ensure there is enough lubricating oil within the system. A very good ratio of PAG, or ester oil to refrigerant capacity is seven ounces of oil per pound of refrigerant in the system. Too little oil and the compressor does not last. Typically the aftermarket suppliers are using either a Sanden compressor, or a variant of the type. These have a sump with a plug in the side of the body. With the compressor level, remove the plug, and fill the sump with oil to the bottom of the threads in the body and replace the plug. Remove the plugs in the suction and discharge ports and pour about 1/2 ounce oil in each and turn the compressor clutch slowly over by hand. When you have made about six revolutions of the clutch, install the plugs back into the compressor ports. Now either install onto the engine or place in an out of the way place so you can lose it............

After you mount your condensor, evaporator and ancillary equipment and just before running the linesets, pour about 2 ounces of oil in the condensor, and evaporator with the balance in the receiver/dryer, or accumulator. Figuring about a 2 pound refrigerant capacity system you will now have between 12, and 14 ounces total oil in the system and this is enough to get started. I then install the lineset(s), (lubricate any "O" rings with refrigerant oil) and tighten to proper torque. Use ample clamp to secure the lines from the enging mounted compressor to the evaporator and condensor also.

As Thad stated pull the system into a deep vacume in excess of 29.75 inches and let the system dwell with the vacume pump running at least two hours. One step further I take is to introduce 50 psi of nitrogen into the system and allow it to set for at least 30 minutes to extract any remnants of moisture check for leaks/integrity. After passing these tests, the system is again pulled into a vacume for a couple minutes. I then introduce liquid refrigerant into the high side charge port while the refrigerant bottle sets on a calibrated scale. When there has been one pound of liquid refrigerant introduced into the system, I shut the flow off. This is allowed to stabilize and "flash", or evaporate into a gas within the system so the compressor is not "slugged" upon startup. About two minutes is enough but if the system is started immediately and liquid refrigerant hits the compressor, it's bye bye time for the valves in the compressor.

At this time you can engage the system and begin to introduce more refrigerant in the form of gas into the low side, (suction port) of the compressor. Dependent upon the ambient temperature of the air will dictate your compressor discharge pressure but stay below 300 psi at all times. Most R-134 systems will not let you exceed 350 psi as a safety precaution and will shut the compressor down by releasing the clutch. With the windows closed in the cabin keep charging and looking for about a 33-35 degree evaporator temperature as indicated on your suction, or low side gauge that is blue in color. Using R-134 refrigerant with an ambient temperature of 90 degrees F, you should be about 255 psi to 270 psi dependent on humidity level. Don't overcharge the system as efficiency degrades quickly and loss of cooling is the result. Watch closely as you near the 33 degree temperature because I've seen several times a guy walk away and introduce more refrigerant than needed with less than desirable results.

Most of Red Dot's roof mount units have a built in fan to pull air across the roof mounted condensor so you will not need a fan. If you use a front of radiator mount condensor coil you would need to place a box fan to blow cooling air across the coil.

Keep note of how much refrigerant has been introduced into the system via the scale. When your low side suction gauge reads about 30 degrees run a calculation of how much oil the system is still short assuming the seven ounces of oil to refrigerant ratio and continue to introduce the needed amount of oil. The refrigerant will circulate it within the system.

Rob

Just aint no doubt bout it Rob, you are indubidably handier than horns on a billy goat! I printed that out, made a lil presentation cover for it and titled it "Robs AC bible". really do thank you and thad for help, will keep you informed of progress when i get started. prime minister randy