How long should it take?

[BrianB]

I feel kinda'...ummm...weird? asking this question. How long should it take for the interior of a machine (Westinghouse 44SK) to cool down to the proper temperature? The machine is half full and sits in a room that is approximately 72 degree's F.

I got the refrigeration deck re-installed last night after pulling a vacuum on it and filling it with R-12. I plugged the sucker in and watched to see what happened. The first few rows of coils got frosty/slightly icy. I then closed the machine up and left it alon for about a 1/2 hour and came back to check it's progress.

It seemed like it was cooling down ok but not like I expected. The frost was now gone from the coils and they were cool to the touch but quite as cold as I thought they should be and they had some condensation on the too.

As I sat and watched it, with the door open wondering if I'd done something wrong, the control bulb started "hissing" or what I descriobe as pumping refrigerant and the coils started to get frosty again. The whole time the compressor remains running.

What am I doing wrong!?!? Am I just being to impatient or is something wrong with my vintage deck?

[MoonDawg]

One-half an hour is not long enough.  But if this continues.........here is my thought.  One droplet of water in the freon will eventually freeze into an ice crystal. This will then block the capillary tube and cease cooling.   You opened the door, temp rose, ice melted and cooling resumed.
       Did you fill your system yourself?  Did you add a dryer?

[Kevin C]

Hello

I would close it up & let it run for at least 2 hours & then check the temp.

Some items to check.  Fan motors, T-stat.

Kevin

[BrianB]

Thanks for the quick responses guys.

Glen, yep, I charged it myself. I was given a vacuum pump by a buddy of mine for free and acquired a Uniweld Gauge manifold and a set of older, but still good, Robinair hoses. I vacuumed it down and weighed the R-12 in and everything seemed great.

Maybe I'm just not waiting long enough. I've been known to be impatient at times!

You're gonna want to smack me for this one though.....I didn't switch out the drier..... '> So....I can always remove the old one and replace it with the one I just bought but didn't use  '>

Question(w/ a statement first!): on the cap tube side, I know that I'll have to cut the tube and swedge/crimp the drier onto it and then solder. Do I do the same for the condenser side? Or should I use a sleeve union? (the condenser side is larger than the drier side)

Kevin - I'm pretty sure the (like 95% sure) thermo. is good to go. I got it from another WC-44SK that was being parted out. The fan motors are good to go also, they used to be three wire fans that went kaput and I switched them out with a couple 5 watt motors that work very nicely.

Thanks for the help fella's!

[BrianB]

Welp......I ran the machine last night from around 5pm to 10pm. The bottles felt like they were getting cold but is it normal for the compressor to run that long to cool the interior down?

I would have thought that it would have at least reached the the lower end of the thermostat's responsive tolerance. But, it didn't. The only good thing I guess is that it didn't go into a thermal overload state. At least it's getting good airflow across the coils.

On a lighter note....(yeah right) I called Eric at Global Compressors yesterday about my issue. He asked me the all important questions including, "Did you change the drier?" I guess he knew the answer by the 7-second dramatic pause. Sooo.....after getting schooled real quick like, I came to the realization that I'd go home after work and plug it in to see if it would cool down and then I'd make the determination on what to do.

I'll end up removing the deck and replacing the drier and checking for any leaks.

[BryanH]

Brian - hat's off to you for tackling the refrigeration system.  I always assumed the systems were closed for a reason '>. Do you have a background/training in the area or just a can-do attitude? Any chance you took any pictures of the process?  Would love to have a reference should I (or anyone else) decide to tackle the 'last frontier' of restoration.

[BrianB]

Thanks Bryan! Nope, no formal background/training. I have a buddy of mine that works for the Public Works Dept. on base (where I work as a Dept. Of The Navy civilian) who originally came by to respond to an A/C problem/trouble ticket our building was having.

I mentioned to him that I had an old soda pop machine that need some "help" and he offered his off-the-clock expertise and I sorta just latched onto him!

One of the guys in my Naval Reserve unit just so happens to be a very experienced A/C & R technician. I told him that I was having trouble locating a good vacuum pump for a reasonable price (a new pump goes for anywhere between $165-$378) He gave me a slightly used one for free!! And then I snagged a set of R-12 gauges/hoses off of GreedBay for cheap.

It also helps that I have a really cool bunch of guys that staff a local A/C & R shop. They carry everything I need to either repair/build a new deck.

Eric at Global Compressors has also been a tremendous help, as usual! '>

Probably the most challenging part of the entire process for most is learning how to solder correctly and then secondly, following all of the steps, pressure testing for leaks, vacuuming down the system and finally, charging the system.

As you have read, I am still learning. I have made some dumb '> rookie mistakes, but such is life! I was fortunate enough to acquire about (13) 12 oz. cans or R-12 on the cheap, $5 a can!, from a buddy of mine who is getting ready to retire and move out of state!

With that being said, I had some wiggle room as far as having enough refrigerant around to charge/re-charge a system and not trip out to bad!!

Oh yeah!! Anybody that has seen R-12 for sale on Ebay and read the legal disclaimer about being EPA Certified or only buying to resale, you can get MVAC Technician Certification (EPA Clean Air Act Section 609) certified by taking a 25 question online, OPEN BOOK (available at the website in PDF form), test that you can get 5 wrong on and become certified by the EPA to handle/purchase/work on any system containing a variety of refrigerants most notably to include R-12. 10 minutes and $19.95 later and you are good to go! The company that I used is
<a href="www.qwik.com" target="_blank">Mainstream Engineering Corporation</a> You'll receive an official card in the mail a couple of weeks later! '>

I'll snap some pics of my stuff and transpose some of my notes when I do my next basket case!

[globalcompressors]

Brian,  

What's the scoop? Did you get the machine running? You mentioned the unit ran for about 5 hours. Is the machine full of product and outside? I can't remember if you said it's in a garage or not. You want to use a thermometer to check the temperature. Put it in the despencing area as not to open the main door. Usually on an empty machine, it should take around an hour or so to cool down. If it's full of product and outside, maybe 2 or more hours. What is the low side pressure after running an hour? If the box temperature is around 40-45 or so, the pressure should be about 8 psi, give or take a pound or two. If you are lower, or in a vacuum with frost creeping back down the cap tube, at the evaporator coil, you still may be undercharged. Remember, these units only hold around a pound (12-16oz) or less of freon, newer units even less, about 8oz or so. Sounds like you're getting there.

Practice, practice, practice, and a little patience.

Eric:)