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What is the proper method to charge an ice cream machine with an AEV. Liquid subcooling, liquid line sight glass, suction superheat, weigh in, etc.??? There aren't many types of equipment manufactured these days that utilize an Automatic Expansion Valve!
Hi Terry.
I would charge slowly using the sight glass ( thats what it there for)
let the system balance and add more refrigerant. I belive there is a hot gas bypass there as well.
top it when it is about 2-3C from set point.
It takes some time to fill and balance but this way you will be doing it once.
Good luck
Chemi :)
The Taylor machines I am working on do not have sight glasses installed. So, am I to assume that, after the system has run a while and balanced out, I should have some sub-cooling in the liquid line?(No bubbles) If so, how many degrees of subcooling? Does the suction superheat matter?
I did not know you could still get an AAV these days! I haven't seen one since the 60's.
I would initially treat it as an orifice or capillary, you could, in theory, charge by pressure and frost line, but that is hit and miss. Doesn't the manufacturer give a charge weight? That would be the easiest option.
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Ford R-Series specifications
Taylor machines are tough to charge correctly unless you evacuate & weigh in.
One difference between an AEV and cap tube charging, assuming you have the manual with the AEV setting listed and no one has adjusted it, is that you stop charging when suction rises to the AEV setting.
By that time, your mix will be 1/2 done or more, normally. If you're lucky, as the mix hardens and load drops, you don't frost past the suction valve.
If the AEV has been played with or if I'm not sure if it is correct, I use an electronic sight glass before the valve before I start charging.
Good luck,
Rog
Hi All,
I am assuming that the unit has a drier on it to be replaced, could you not get a sight glass and fit it after the drier.
Weighing in really is he only proper way to charge it, at least that way you know that you have put the design amount of gas in and then could also show up if there are anymore problems
Regards
Raymond
In a critically charged system, a sight glass usually leads to an overcharge. It is useful for checking moisture, but without a receiver before the sight glass, and especially with a drier involved, only an overcharge will clear the glass, in my experience.Quote:
Originally Posted by rdocwra
This seems to be true for any critically charged system with the evaporator above the condensing unit.
Rog
The only proper way is to weigh in the charge. For Taylor units the AEV should be set at 18 psi, however, I found that at this setting the unit floods back so I set them at 14 psi and they work great. Do yourself a favor and ALWAYS weigh in the charge, saves alot of agravation later.
Chill
hi i have tree soft ice cream machines to repair and i'am becoming crazy at this moment i arrive to an orifice nē5 assembly in an termostactic expansion valve the charge is 1.9 Kg of r 404a all this in a machine with 30 years .all the things i've readed about making soft ice cream says that we have to do it quikly and the variation of the temperature in the cilinders shouldn't be more than 3ēc to prevent crystal in the moisture so the recover after stopping should be quick with the orifice nē5 i'm not beeing capable to do it i will try the nē6 and after i tell you something sorry my inglish but i do not write for a wile i am in portugal
This is how we where tuaght as well only to charge by super heat and treat it as a critical charge system.Quote:
Originally Posted by Argus
On a Taylor Soft Serve Machine it is a critical charged system. If you are replacing a R502 with the new R408A you want to charge it to only 80% of what the ID tag reads. Your low side is adjusted to 18-21 psi, on the high side in a room that is 70 degrees you should see 255 to 270. If you are dealing with a water cooled unit the high side is set to 255. the low side is still set at 18-21 psi. The temp of the product coming out of the machine should be 16 - 18 degrees. I run a temp of 18-21 finished product. If the blades are dull then replace, dull blades will make the product come out soft (limp) always take the temp of the finished product if you are having problems. If the temp is around 16-18 degrees then the machine is doing what it is made to do. Changes the blades or if the product has sat in the freezing cylinder to long is has broke down ( butter fat seperated) This will also cause the product to come out soft. The blades should be changed every two months or more often in heavy use.