Upright Commercial Freezer

[BlueVanACD2005]

I bought a used freezer, and it all looks nice, but it won't get very cold. Now I know this is a pretty general problem, so I'll provide as many details as possible to try and narrow it down. It's nothing electrical - the compressor is getting power and both fans run. The defrost coil isn't stuck on or anything like that either. It will run non-stop, and only get down to about 35 degrees F. I noticed that the evaporator coils only get really cold and frosty near the capillary tubing... Maybe approximately the closest 6 or 8 inches. I'm unsure of what this may mean though. Is it low on *****? (It takes R404A). It has saddle vales on the high and low side, that I can tell were added after manufacturing... Maybe they had problems before?

http://i108.photobucket.com/albums/n19/bluevanacd2005/HPIM4302.jpg
http://i108.photobucket.com/albums/n19/bluevanacd2005/HPIM4291.jpg
http://i108.photobucket.com/albums/n19/bluevanacd2005/HPIM4293.jpg
http://i108.photobucket.com/albums/n19/bluevanacd2005/HPIM4294.jpg

Thanks!

-Spenser

[paul_h]

I'd say it's short of refrigerant or a partial blockage.
It probably did have previous problems and thats why the previous owners got rid of it :D
They look pretty similar to the skope and williams cabinets and use a high TD and critical refrigerant charge that needs to be weighed in by the gram exact.
Capillary blockages are fairly common too on these.
Needs a reclaim, good nitrogen blow through and pressure test/leak repair and r404a weighed in the the exact amount.

[BlueVanACD2005]

Needs a reclaim, good nitrogen blow through and pressure test/leak repair and r404a weighed in the the exact amount.
Hmm... Wonder how much that might cost... :eek:

[paul_h]

You're better off phoning local refrigeration companies, rather than any of us speculating what they may charge.
If you tell them what you need doing and what the refrig charge on the label is, they'd be able to quote.

Make sure the freezer is off and fully defrosted though, makes it easier to reclaim, get any blockages and moisture during blow through and evacuation.

[BlueVanACD2005]

Alright, I was thinking about calling around tomorrow anyway.

But if there was a blockage in the capillary tube, wouldn't the condenser coils get real warm because of excess pressure?
If so, I doubt thats the problem because they barely even get above room temp (when I hold my hand on them, it's hard to tell they're warm at all).

[paul_h]

No, liquid backs up in the condenser, so more liquid than hot discharge gas in condenser, more sensible heat lost off the liquid to the air than a normal system. Less refrigerant coming back due to low flow from evap, less discharge gas being added to condenser.
So a restriction lowers condenser temps too.

[mickeyd378]

Refrigeration leak, system running low on charge

[philfridge]

A simple one to diagnose unit is short of gas simply get an engineer to top up refrigerant charge and leak test or replace cabinet as once youve got al eak gas will leak out again and you will be back to square one.

[paul_h]

These are a "drop in" style unit, not complete one piece as the insulated evap box is part of the fridge, but the whole refrig system lifts out, no need to buy a new fridge. The refrig unit is completely serviceable.
And you can not "top up " these units, they are capilliary and very critically charged

[philfridge]

And you can not "top up " these units, they are capilliary and very critically charged


Paul I have to disagree with this remark as its nonsense ive been regassing capalliry systems for over 20 years succesfully :p

[paul_h]

If you've topped up any of these commercial systems I'm all ears. I've worked on williams, skope etc and they are all deliberately undercharged, ie. long capillaries just to make max TDs for the evap size. Try to charge any of them for decent superheat or subcool, the system will be way overcharged.
Ever charged a regular 500L freezer with just 330gram r404a? That's how little some of them take.
edit: All cap systems are critical charge and can not be "topped up" Let alone the fact you are dealing with the existing issue, ie leak or blockage, it needs a nitrogen charge to check for leak, and a vac anyway :)

[BlueVanACD2005]

Well, I called around and it'll be about $100 to have someone come out an re-charge it. But is there any way to make sure this is the problem before I spend the money on it?

[philfridge]

On closer inspection of the pictures now been added ive seen as paul stated it is a serviceable cabinet . The prognosis stays the same :) system short of gas and possible gas leak to evaporator coil which is common to this type of unit.

[BlueVanACD2005]

Well, in that case I'm thinking of just calling that guy and getting him out here for $100... He'll have the gauges so we'll be able to see what we've got. If it's just low, we can re-charge it and see how long it'll last. If it's a bigger leak, I'll try to find it and get it fixed (by 'bigger' leak, I mean it might get too low to cool right in a couple days or a week). If it's a smaller leak, I'll probably just sell it while it's working (and by 'smaller' leak, I mean it might get to low to cool right in a few months or a year).

[paul_h]

You can't tell how big the leak is until you find it, and then you might as well repair it :D
There's no point in paying someone $100 x 2 callouts just to find out how big the leak is.

[BlueVanACD2005]

Well... What if it's not a leak though? What if the compressor's bad or something? I figured the first callout could determine exactly whats wrong with it, and the second could fix it (or the first, depending on the problem).

[paul_h]

Well if something else is wrong you shouldn't be adding more refrigerant as there's no point/need, so you answered your own question.
My answer wasn't addressed to "what if" situations.
If it is proven to be short of refrigerant, and being they are critically charged, best option is to try find the leak.
If they can't, reclaim, bump up with nitrogen, retest for leaks and repair, then evac and recharge from scratch.
If you top up these fridges, it's bad, as you can't dial in the correct charge by pressure or temps by their design. (edit: you can, but you'd be paying more in labour for a fridgey to stand next to it for 2 hrs, rather than let them go hammer and tongs on it with nitrogen, leak detector and a vac pump for an hour.)

Also topping up without leak testing may just get your freezer broken again as the leak wasn't fixed, then you'll be $100 poorer and is the exact same situation a few weeks/months from now. If it's worth doing, it's worth doing right.
I'd be out of a job if I just charged refrigerant into systems low on refrigerant, it's illegal in most countries without attempting to repair the fault. It's probably not illegal where you are, but it's costly and incovienient to pay $100 for a top up that needs redoing every few weeks or months.

[taz24]

I bought a used freezer, and it all looks nice, but it won't get very cold. Thanks!

-Spenser


Well going by the photos it is obvious what the problem is and I'm suprised nobody has noticed it.

CALL YOURSELVES FRIDGE ENGINEERS.

Look on the photo and you will see the fault.......
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:pThere is no lid on the evap.
All the cold air will be blown right out:p

I'm sorry I could not resist.

I'll get me coat..

taz.

[BlueVanACD2005]

All the cold air will be blown right out
Haha nice joke but it can't even make cold air because it's not working right....

But I called the guy and he's supposed to come out... I guess I'll just have him do whatever it takes to get it working right (and stay working right). I suppose I'm just a little afraid of cost is all....

[taz24]

Haha nice joke but it can't even make cold air because it's not working right....

But I called the guy and he's supposed to come out... I guess I'll just have him do whatever it takes to get it working right (and stay working right). I suppose I'm just a little afraid of cost is all....


All jokeing apart I think Paul nailed the problem and it should be easy to repair.
Cost is another thing and unfortunatly your on your own with that one:p

Cheers taz.

[BlueVanACD2005]

Well, I ended up going out and buying my own set of gauges, because the guy who said he'd come out for $100 is just avoiding me now...

But with the freezer off, both the high and low side were about 50 PSI. I then turned on the freezer - and the low side dropped to a little less than 0 PSI, and the high side went up to about 150 PSI both within the first minute or so. After about 5 minutes of running - the low side was about 0 PSI, and the high side was about 175 PSI. Then after ten minutes of running- the low side was about 1 PSI, and the high side was about 200 PSI. Then this is where it stayed even a half hour later, so I stopped checking it after that.

The freezer is rated for 400 PSI on the high side, and 250 PSI on the low side...

So now I'm kinda wondering what all these numbers mean. The way I see it, I still have the same two possibilities as before.

1. It is low on a charge.
2. The compressor is worn out and not pushing enough pressure into the high side.

But comparatively, I hooked the gauges up to the A/C on my van. With it off, both the high and low sides were about 65 PSI. Then after a minute or so of running, the low side was about 30 PSI, and the high side was about 225 PSI. This is how it stayed for a good 5 minutes or so, so I just unhooked the gauges...

[paul_h]

:rolleyes: :off topic:

[albionharley]

Blimey Paul - had a bad day mate ;)

[BlueVanACD2005]

Wow man...

I felt like I had to take it into my own hands when the guy that said he could do it for $100 is obviously avoiding me now for some reason. One of the only other places around me wants $25 to come out, plus $0.40 a mile, plus $77 an hour, plus the cost of materials.... I just don't have that kind of money - I barely had the $100 to begin with.

I realize that almost everyone on here is going to know more than me about refrigeration... Thats why I came on here - I was seeking help. I really appreciate all the help you've given me, I'm not trying to waste your time or anything like that. Also, I am paying attention to what you're telling me. I'm just a little unsure about the whole problem to begin with.

I don't think it's such a bad thing to try and learn something new either... I'm just a little unsure because it's new to me, so of course I'm going to carry a little bit of doubt along with me... I've never really done this before...

Thanks for the help. Spenser.

[BlueVanACD2005]

I just came back to say that I did end up getting it to work. It can easily get to -10 F like it's supposed to now. I couldn't get anyone to come out though, so I ended up retrofitting it with R134A... No idea if it'll last or not, but I guess it doesn't really matter because I don't need this freezer for anything. It was mainly just a hobby kind of thing.

I don't think thats too bad of an accomplishment - it wouldn't get below 35 F when I first got it, and now it gets down to -10 F.

Thanks again for the help,

-Spenser

[philfridge]

I couldn't get anyone to come out though, so I ended up retrofitting it with R134A... No idea if it'll last or not


You mean you just topped it up ! with the incorrect refrigerant you have not retrofitted it :D :D

[BlueVanACD2005]

Nope, I drained the 404A and recharged it with 134A...

[BlueVanACD2005]

Oh, and put a little adapter thingy on the valve to charge it with lol...

I don't know whether or not it's good for it (probably not), but it's not like really need this freezer for anything, so it's just more or less and experiment...

[dingaling]

Just browsing threads - hope I never come across BlueVan man, or buy anything he has owned. What a waste of space - gives amateurs a bad name.

[mikeref]

Drained the R404a?? AND charged it with the wrong gas with a possible gas leak still present? Too many red flags here