– Urgent – Blast Chiller Problems – Urgent –

[olivero]

Went up to the platform, compressor is half covered in frost, went and grabbed my gauges, hooked in and I had about 3-6 PSI suction, SH was going around from 9-10* SH and the suction pipe temp went all the way to -30* I believe it was.

That pan of chicken never stood a chance, loaded at 160*F brought it down to -8* in about 90 minutes.

No error code there. They will be using it a lot this afternoon so I will be perched over the compressor making sure everything runs okay but looks to me like its running good.

 

With a 9* SH at least I am not flooding it, wouldn’t mind it being a little higher but if I start messing with it, it will affect it when its running on its cooling (38* temp) mode and will put the SH higher.

 

is 9* SH too low? Trenton’s tech support is saying I am all good and happy but I like multiple opinions.

 

Got it on the frost, I know its just telling me that my pipe is below freezing and its humid, just never saw it before and was worried I was flooding the compressor.

[fixbear]

How certain are you of the calibration of your gauges and temp probe. Was their calibration tested in the last month.  I always keep a low pressure gauge just for testing and regularly check my temp . Have had to replace a few thermocouples. over the years.  If you have a compressor that is covered in frost, you are getting flood back. It’s ok to have a bit of frost on the head and around the suction valve,  but if you are seeing ice farther down the crankcase and near the discharge side you have a problem.  You really need to monitor a machine like this for twenty minutes.  Better yet through a full cycle.

[olivero]

Fairly certain, I calibrated them about a month ago.

 

Its not the entire compressor, only one half of it where the suction is.

 

If I am getting SH I am not getting a flood back, its 9* above its vaporizing temperature. Again, its a low temp unit, it brings food down to 0* in 4 hours max when its in freezing mode, IT did this pan of chicken to -8 *F in a little less than half that time, now its running in cooling mode and there is not an inch of frost visible on the compressor but the suction line is still below 32*.

 

Pulling the room that low put that suction line at -20 degrees while its running, 404A at 4 or 5 PSI is about -30 degrees so I am not surprised its frosting, I did have the same concern so I know where you are coming from but after watching it run for 20-40 minutes in freezing mode just sitting on an electrical box watching numbers move and never once did it go below 9* superheat while it was on but the suction pipe temp was slowly going down along with the suction pressure until it hit set point and the chicken was -8 *F. I also asked Trentons tech support who made the condensing unit and he told me its pretty common in Florida for low temp units because there is high humidity.

 

Here is something on frost and all that.

Frost And Low-Temp Compressors 

[fixbear]

Ah, you never said Florida.. As long as the TXV screw is not deadheaded to one end, you may be ok. I like the superheat and frost on the compressor.  What’s your take down temp?  How much air velocity does this cooler have? 

[badbozo2315]

>Speaking of, I haven’t seen alnelson or badbozo2315 around here lately. I know bozo is active over there. Any thoughts on that?

 

None.  Nope. Zero. 

 

As some have guessed, I actually work for a PT Holdings sub company, and have been told I need to only post using our company-sanctioned username here, and only in certain forums.

 

Well, we can see how that’s going. 

 

Combine that with turning 61 the other day, now counting the days until I can retire, at least somewhat, and give my knees a break.

 

Also, there is a good group of helpful, knoweldgeable techs at both places, who are more willing to gently guide the young’uns along- as it should be. There’s little need for someone of my calls-em-likes-I-sees-em lambasting of silly-to-stupid shenanigans.

[fixbear]

Nice to hear from you young-in!. Tell them to stuff it. free speech. LOL  Unless they supply the comm device.

[olivero]

Funny how me mentioning Florida anybody I talk to says “Ah, that explains it”

 

Yeah, I screwed it in 1 1/4 turn but seemed like it needed to be opened a bit.

 

Take down temp? Sorry, not familiar with that. I should probably also mention I am from Denmark so some terms may be lost on me, actually, a lot of them are lost on me

 

Its got 3 fans, its a T40 from Delfield’s Convochill series of garb..*** *cough* sorry… I mean equipment.

[fixbear]

“Take Down”  is the temperature drop across the evaporator.  Climate in Florida is it’s own thing. Especially the humidity and bugs. That box has to be a costly item to run.  And I’ve never seen a evaporator mounted vertically. How do they control the condensate and refrigerant flow?  Seems to me that refrigerant distribution, flow, especially when undercharged or underfed would be a real nightmare. 

 

1 and 1/4 turns on a Alco is ok. Sporland, that would be a lot.  You said at one point that you had to bottom the valve. Valve must be under-size for the capacity or you would have flooded it.  Be happy that Delfield run’s on the cheap side.

 

“Take down” is also important in design for application.  If you where building a floral case, you would design in a 5 degree to keep from drying out the flowers.  Dough retarders would be 5 to 8 degree for the same reason. normal walk ins are 10 to 15 degrees.  As you can see, it’s all about moisture control. With that big compressor and 4 by 5 box the take down has to be enormous.. And once you know it for a cooler,  it’s a fast, cheap, and easy way to check capacity.

 

Glad your unit runs ok.

[olivero]

You know, I have no idea how they designed or any of their design specs, I tried to get it from Delfield but they say it’s built in Italy…… I guess that’s a good reason to have no design data?

 

Its an odd thing, it’s a Delfield unit with a Copeland compressor and a Trenton Condensing unit made for Convotherm’s Convochill series

 

I had the same thought, since having to open the balancing valves all the way and the water regulating valve were opened all the way. Then the TXV got opened almost all the way, looks like someone undersized it, wonder if its intentional or not.

 

Is Take down the same as TD?

[fixbear]

I won’t say undersized, but definitely minimal.  I’m certain cost was the primary as long as if “worked”.  Low temp Copeland is the only reliable solution for compressors. Trentons are one of the least expensive condensers for manufacturers.  .Reliability you by Sporland,  Cost Alco.  That specialized chill evaporator is what I’m interested to learn more about.

 

Yes TD is take down.