Hill Phoenix Case Question

[danny x]

I have two island cases,

Model # CIZ-12FK-C
Model # CIZ-8FK-C

The compressor handling these cases is an AH5524E. Each has a FVE 1 1/2C TXV. The valves have recently been changed. I am looking for the set up and operating pressures and temps for this case. I have found a link on the Hill Phoenix website however I am still unsure on which line my model falls on.

http://www.hillphoenix.com/information/data_sheets/Classic_Case_Operation_Guidelines.pdf

The problem with the case is the suction pressure runs down real low (20 PSI) in order to pull temp (36-38) on these cases. I am unsure of where my suction pressure, and cut in/out should be for these cases. If I interpret the chart right I think it should cut in at 44 PSI and cutout at 30 PSI(for a medium temp case).At those pressures I wonder if the proper compressor was selected, this compressor is rated at 45 degrees, warmer than these operating temperatures.


Thanks for the help

Danny

[NedFlanders]

I'd raise the cut in to to at least 60# (I'm assuming R22)
If you are running the whole rig on straight pressure, you need to spread the cut in/out apart. At 44 you're just getting above your desired evap temp.
If the system is just sized wrong(comp vs case) it will be tough to set up.

I like to set my cut in at my max. desired discharge air temp.
Cut out in you situation, may be lower than ideal but, if set up right should work. 20 # is low but it is what it is.

There may be sizing issues , that's where you may have a problem.

You can't do a t-stat on either case , because it sounds like it wants to pump down already.

Spread the IN/OUT apart to give the comp some run time and off time. You don't want a comp going on/off constantly.
somwhere in the middle should be the desired operating temp.



If they are the same model cases they should run real close in temp as long as you superheats are good.

[danny x]

Well I will say that this is NOT a text book installation (typical hacked in system on cases from 88), and that is an understatement. The cut in and out I chose was from the chart I posted a link to (although I am still not 100% sure I used the right line). I would use 60 PSI as a cut in however the case would warm up significantly if I did(As in I tried 60 PSI). Both cases are on the same condenser, there is a 1609-101 control on the case, however no solenoid, it just breaks power. R22 is the refrigerant.

If you look at the link I posted, it looks the the model number of the cases falls under index R for island frozen food, icecream.

For all I know these evaporators are ported for low temp, and that may be why the pressure wants to pull down?

[Dowadudda]

CIZ not C but CIZ F. Index letter K.

12' and 8' is low temp island Frozen Food. Index K

That is if I am reading your model correctly. If it was CIZ8C, it would fall under designation R, But it is CIZ8F. The C at the end is for something else I believe.

Either way. R or K. Your using low temp cases with a medium temp pump.

So now you have Condensing unit at MT rating. It's obviously not going to work right. So you have to jerry rig it. I bet you have been told it's been working like that for a long time. It's a shame isn't it?

[icemeister]

The Hill info I have says the CIZ for frozen food requires 416 Btuh/ft at -28ºF ET and -16ºF discharge air. This case can run medium temp (but I seem to have lost the Hill load correction factors). A data sheet I have from Tyler for sizing a similar low temp case with a requirement for FF of 420 Btuh/ft at -25ºF and -15ºF DA says that at the medium temp range it requires 333 Btuh/ft at +15ºF ET and +24ºF DA.

Sooooo.....using that, for your situation I estimate that 20 ft of CIZ at MT would require 20 x 333 Btuh/ft or 6660 Btuh at +15ºF ET. The AH5524E at that condition has a capacity of 14,683 Btuh.....or waaaay oversized. That might explain the low suction pressure. A Tecumseh AJA9486EXDXC unit should do well on this application.

The TEV's are also way too big at 1 1/2 tons each. I'd go with a 1/4 Ton valve for the 8 footer and 1/3 ton for the 12 ft case.

After all that, you might get this system running well enough to set the controls properly.

[danny x]

CIZ not C but CIZ F. Index letter K.

So now you have Condensing unit at MT rating. It's obviously not going to work right. So you have to jerry rig it. I bet you have been told it's been working like that for a long time. It's a shame isn't it?

Yep, new account. Yep, "It's been running like that for 20 years"


The Hill info I have says the CIZ for frozen food requires 416 Btuh/ft at -28ºF ET and -16ºF discharge air. This case can run medium temp (but I seem to have lost the Hill load correction factors). A data sheet I have from Tyler for sizing a similar low temp case with a requirement for FF of 420 Btuh/ft at -25ºF and -15ºF DA says that at the medium temp range it requires 333 Btuh/ft at +15ºF ET and +24ºF DA.

Sooooo.....using that, for your situation I estimate that 20 ft of CIZ at MT would require 20 x 333 Btuh/ft or 6660 Btuh at +15ºF ET. The AH5524E at that condition has a capacity of 14,683 Btuh.....or waaaay oversized. That might explain the low suction pressure. A Tecumseh AJA9486EXDXC unit should do well on this application.

The TEV's are also way too big at 1 1/2 tons each. I'd go with a 1/4 Ton valve for the 8 footer and 1/3 ton for the 12 ft case.

After all that, you might get this system running well enough to set the controls properly.

Thanks Ice, this was really helpful. Too bad when I explain this to the store owner he’ll look at me like I am crazy. Nothing like adjusting the pressure control 5 million times to keep the case cool enough without freezing up the evporators.

Are these calculations standard for island cases? I realize it may differ from model to model, but can the 333 and 420 be used as a rule of thumb?

[icemeister]

Case loads and evap temps vary quite a bit actually. It's always best to get the correct info. Some of the older stuff is hard to find these days, but you can ask here or you can always call the factory.

The 333 Btuh/ft figure that I got from my dusty old Tyler book wasn't a published number either, but was on a special sheet they had for estimating MT loads for some of their LT cases....ie, those typically used as dual temps and such.

I've had (and still have) some cases that are problematic like yours. The customer doesn't want to hear that their case was set up all wrong because in their mind they've been working fine all these years. I usually just inform them of what should be done to make it right and go about trying to baby the systems along until they finally quit. Then I have a much better chance to make things right.

For example, I have a meat market customer with a 60 ft run of service meat case that was tied to a 4 hp CR Copelaweld. This system always ran about 10-15# suction on R22 and cycled way too much at that. The compressor eventually cooked and I changed it out for a 2 hp CR. Now it really runs sweet. :)

I've got another store with a 5 hp semi R22 MT running two 8 ft service deli cases and a 2-door reach-in.....and this was selected by Hill/Phoenix factory!!!:eek: (I saw the HP load sheets. Somebody apparently had failed arithmetic);) I'm waiting for that puppy to die, too.

[Dowadudda]

I always get a kick that Ice gets after this info for you guys on here. I like swapping spit with everyone on here, but retreiving the info for someone else, I am too lazy to do it for other than when my a$$ is in a bind.

And of course, I have had Ice help me out. So. Good going Meister.

You could make some bucks off this by making your own website. :D

[icemeister]

....Good going Meister.

You could make some bucks off this by making your own website. :D

Thanks, but that would take the fun out of it.;)

So I think I'll just stick with my day job.:D

[danny x]

People like Ice are what make this message board the best on the internet for contractors or technicians that are unsure or unable to get information they so desperately need, or might be embarrassed to ask someone about. Unlike some of the other email/message boards out there this one doesn't cost me $50 a month whether I visit or not (and for a small contractor like myself, that $50 goes a long way).

Thanks for not being lazy Ice or charging me for the info in some book that’s touts how it will help me be more successful. 15 minuets of your time typing save me hours of adjusting, experimenting and trying to call people who might know.

Danny

[icemeister]

Thanks guys for the kind words. I do it because I enjoy this business and I want to share something of what I've learned along the way.

Danny, the only thing I want in return if you eventually get a chance to redo this system per my advice.....and if it works.....is if you're ever in town just look me up and saythese two things..... "Let's meet for lunch and I'm buying.":)

Dow, that goes for you as well, but from what I hear from the MI boys, you'd certainly be up for the eats, but that second part would be totally out of character, ;) :D :D :D :D

But that's OK, I know a lot of places where I can eat free anytime I want.

I'm cheap too.:p :D

[Dowadudda]

Don't let any of my brothers in arms fool ya. There cheap when there broke too..:D :D :eek:

[dirtyboy103us]

ICE i will buy lunch anytime just to put a face and a voice to the all the post i have read and just pick your brains but i'm afraid it would last about 6 hours for a minimun

[danny x]

I took your recommendations, and it works like a charm. My cut in cut out is set at 32/45. The coil hasn’t frozen since the replacement. The suction pressure doesn’t immediately plummet like before or short cycle. I have been able to maintain between a 27-28 supply air temp and a 36-38 degree case.

I have another match up question. Same store, different case. Same type of problem, the suction pressure plummets and the coil freezes up after a few days.

I don’t have a model number however the case is similar in design and color (if that helps). The case is 12’ long. The tag for the condensing unit has been removed however someone in the last few years has replaced the compressor with a LACA-032E-TAC-800. When I called United they had said the compressor was rated for 502/22 and has a btu rating of 17,000. I tried looking up the compressor and the information I found said it is rated for 404/134/507, not 502 or 22.

First I was wondering if there was a link to more specific information (the Emerson site sends me round and round) and second is this compressor the right selection for this application.

Thanks

[icemeister]

Do you mean you changed out the compressor....and it worked?;) WooHoo!!!

It appears that you have a similar situation with this case. That 3 HP Copelametic is way too big for that case at medium temp any way you slice it.

Assuming this case is also a 12 ft CIZ or similar single wide coffin style frozen food case, at medium temperature we're still talking approx 333 Btuh/ft or around 4000 Btuh at +15F. You didn't say which refrigerant you're running with this LACA-032E compressor, but even if you ran it with R134A (which would give the lowest capacity) it'll be oversized with a capacity in the neighborhood of 20,000 Btuh at +15F/120F.

I'd pick a small 3/4 HP unit for this one like an AKA9460ZXDXC R404A which would give you about 5000 Btuh capacity at that range. Stick with something with POE oil since that's already in the system from that 32E pump.

[danny x]

Well, I changed the condensing unit, built a condensing unit rack to pull the unit off the floor, remounted the time clock and pressure control to the rack and piped the suction liquid line to look more professional instead of the spaghetti mess that was there. Oh, I changed the expansion valves too. I took some pictures of before and after but just need to figure out how to get them out of my cell phone camera.

This new case is set up as a frozen food case, not medium temp, it is the same size, shape and color as the CIZ case so I am assuming it is a CIZ. The gas currently being used is 408. The condensing unit united selected was a FJALB301TMFC010 3 HP rated at 5900 BTUs at a -30 suction temp. Does this selection make sense? Obviously I am not that great with coffin style cases.

Thanks for the Help

[icemeister]

....This new case is set up as a frozen food case, not medium temp, it is the same size, shape and color as the CIZ case so I am assuming it is a CIZ. The gas currently being used is 408. The condensing unit united selected was a FJALB301TMFC010 3 HP rated at 5900 BTUs at a -30 suction temp. Does this selection make sense? Obviously I am not that great with coffin style cases.

Ohhhh, so it's actually set up for LT. That's a horse of a different color, but the oversize problem persists according to my numbers.

The LACA-032E is essentially the same as the old model LAC1-0310 which in its day was dual-rated for R12 MT and R502 LT applications. That pump on R408A should run fairly close to the old R502 ratings at LT and as such the capacity at -30F/120F is about 9850 Btuh, or nearly double the case requirement, again the most likely cause of the low suction you're seeing.

The FJAL 3 HP unit would work much better IMHO. A 12 CIZ needs 466 Btuh/ft or about 5600 Btuh at -28F ET, so you're right in there where it should be.

The coil icing condition, while it may have separate issues, could be an indirect result of the existing oversized compressor since your evaporator temperature would be well below design. Normally, one or two defrost terminating at 50F discharge air temp should do the trick.

Good luck on this one, too.:D

[Dowadudda]

your getting all the good calls. I am jealous. NOT. :D