hey RM,You didn't ask this but here goes: did you know that butane is a refrigerant, a flammable one but one that is interesting because you see the effects of ambient temperature on its boiling point. Take a butane lighter and hold it in your hand, get it nice and warm and it will light every time. take the same lighter and put it in the fridge for an hour, take it out and try to get it going... you can't, not till the heat from your hand warms the butane up enough to boil it and create gas and enough vapor pressure to drive up to the flame holder. Ever notice how a propane torch gets cold the longer you run it, and the flame gets smaller? That's because the vapor pressure in the canister of propane is getting lower with the temperature of the remaining liquid. Propane is also a refrigerant, a really good one actually. When the liquid refrigerant gets cold its boiling point goes down as does its vapor pressure. This is what the black and white temp chart is showing you for 134a. I used butane as an example because a lighter is something anybody can purchase, experiment with and see the direct results of vapor pressure.
On to what you did ask:
You can't do AC work without gauges, a vacuum pump and a decent kitchen thermometer (goes in a vent in the car to measure temp delta between ambient and refrigerated air).
I have a set up from harbor freight, yeah, yeah, yeah, get over yourselves; for the DIY'er they work fine. Get the good pump, not the cheap one, it pulls down to 3 microns vacuum.
Answers to your questions:
1) 0.90Kg max is the physical weight of the liquid refrigerant put into an evacuated system. If you look at the side of a can of 134 it will tell you how much is in the can. For example the black and white cans in your pic show 12 oz (340 grams) you need 900 grams, the cans are 340 so 900 /340 = 2.64 cans for a max fill. I'll let you do the math for the min fill.
Always add refrigerant through the low side, The first two cans can be run in, but you have to weigh the third can on a fish scale, with the hose attached, to ensure you don't overfill the system. Sometimes the system will be perfectly happy at the min fill value, still have to weigh the correct amount of refrigerant. Getting the second can in, and the partial third, can be a long process. As the refrigerant boils off in the can and becomes a gas, it cools the remainder in the can, the colder the can gets the lower the pressure in the can. (see the black and white temp chart you show) When the temp of the refrigerant in the can, and its subsequent pressure, is lower then the pressure in the system, it stops feeding gas into the system, and you can wait for the can to slowly...oh so slowly... feed gas into the system or you can force the process by raising the boiling temp of the refrigerant in the can by dunking it in a pan of warm water.
2) you add the new oil into the new dryer before you attach it to the system. It will distribute itself around when the system is running.
3) Answered with 1
4) The temp chart you show is the pressure 134A is at in a still (not moving) system at the temp shown. If you hook up the gauges to the high and low side and the system hasn't run for a good while the pressure across the gauges will be equal. At 75F the pressure =78.7psi. Near on useless information except to tell you there is indeed refrigerant in the system.
The meaning-full chart will compare the low and high side readings at the ambient temp.
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5) mostly answered with 1, as for measuring air or moisture in the lines, you can't. That's beyond the DIY'er. If that's the concern, take it someplace, and have the refrigerant recovered (not for you to reuse, just so its not released to atmosphere). Then change the dryer, draw a vacuum for an hour or so and fill per recommendation.
I suggest you go to the Sanden web site and poke around their technical data.
This is their quick trouble shooting chart.
Here is some of their tech bulletins. Even if you don't fully understand them, read through a couple, it will boost your general understanding of AC systems.
thanks a ton for that. the practical butane/propane examples are super. working though the links now.
on the numbers some of it can get tricky so in case someone is following along i thought i would post a breakdown.
for what it is worth i always get thrown with ounces. for some dumb reason i sometime assume it is a volume measurement in cans like that.