TYLER SERVICE DELI CASE

[DETERMINED]

At one of my stores I have 3 Tyler Service Deli Cases.Vertical Perminant Glass front. Do not have the Model Number. Gravity serpentine coil in the bottom of case and traditional aluminum finned coil in the top of the case. No fans all gravity. R-404A, has a Liq Line Solenoid, and a ORIT-PI Valve on the Suction line. The TXV's feed the bottom coil first and the top coil after. It is controled by CPC E2. The problem is that according to the dept manager this bottom coil has been icing up every month for the last three years. I just got this store in March and have been trying to figure out what is going on. I replaced the LiqLineSolenoid, it is working properly. It has one defrost for 120minutes every 24hours as per the specs. The PI valve is set at 55psi. Anyone run into anything similar or have any advice? Thanks.

[DETERMINED]

To better explain who I am and what I do. I am a refrigeration tech for a supermarket, I have an AAS Electrical Construction and Maintenance, 3 years experience in refrigeration piping and install, and almost a year in as a service man I could consider myself an apprentice. Appreciate any advice or help.

[R&J-R]

Factory Superheat and what Superheat is currently? Is there a myster in the mix?

[DETERMINED]

I haven't checked the superheat year. There isn't a myster. There are pans covering the bottom coil under the product that from what I was told weren't always there. I will check the SH tomorrow morning.

[DETERMINED]

superheat yet***

[R&J-R]

Check out the HillPhoenix website and see if one of their service deli cases match what you have. They used to be Tyler and still have Tyler model specs.

I have no formal training so my terminology is found wanting. Take superheat readings on the suction line at the evap coil. That's pressure and temperature. Subtract pressure saturation temp from sensible temperature and that's your Superheat. Then cross reference with the hopefully found Tyler case listed superheat. If your SH is higher than the listed SH, see if theres an inlet strainer on your TXV's. Pump down and isolate the cases and clean those inlet strainers if they exist. If found clean or non existent then tune the TXV's accordingly to match spec sheet.

What does the E2 say about reciever liquid level? Visually double check the reciever level and check for capacity. Hope my broken tech talk helps.

[DETERMINED]

This is a Tyler Enviroguard II rack. Receiver exists but is not used. They use the Condenser as the Receiver. What would receiver level have to do with this coil icing up?

[R&J-R]

The Hillphoenix cases that I have had the displeasure working on had stainless lids (horribly designed) separating the suction lines from the product. Then pans above the lids to hold product. Because of natural convection there's no need for airflow to circulate through the case.

[R&J-R]

This is a Tyler Enviroguard II rack. Receiver exists but is not used. They use the Condenser as the Receiver. What would receiver level have to do with this coil icing up?

Just checking to see if your refrigerant level is starting to get low. Most times systems/cases located further from the rack will show signs of starving. Starving = Icing. I've never seen a rack setup to not use a reciever. I've only been in the trade for 5yrs. To my knowledge having liquid in the reciever shows that you have sub cooling and adequate capacity. I'm told a rack should show atleast 40% reciever level. Though I've seen racks work on allot less.

[gwegiel]

I have had the same issue with some similar Hussmann cases. I actually set the defrost to run for 8 hours throughout the night since that particular area of the store is closed at night. They also pull product and clean the cases nightly. No reason to run the cases when they are closed anyway! Could be a solution if you have the means. I am also not saying that you shouldnt be checking SH and all that as well.


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[Riverguy553]

Service case should not have a liquid line sol anyways, they should have a suction stop using a t-stat and also have an epr on line up. I also try to set the defrost time to when they are loading the case in the am.

[jpsmith1cm]

Make 'em clean their dang case more often

[John Markl]

Service case should not have a liquid line sol anyways, they should have a suction stop using a t-stat and also have an epr on line up. I also try to set the defrost time to when they are loading the case in the am.

You've got me curious....explain?

I have two identical stores with service delis.....Tyler.

But they only have coils with fans in the bottoms. I did see, where these cases originally had LL AND Suction solenoids, but somebody before me took the LL solenoids out. They run on T-stats, but ironically are on the only circuit on that rack that does NOT have an EPR....as originally installed in '98.

[lovetowork]

Like original poster said, line up has a solenoid and ORIT valve. Cases should be set up to run off of the ORIT with the LLS set 4-6 degrees cooler, so that it is always open and just closes if the case gets very cold.

[mjm88]

Like original poster said, line up has a solenoid and ORIT valve. Cases should be set up to run off of the ORIT with the LLS set 4-6 degrees cooler, so that it is always open and just closes if the case gets very cold.

I was just working on a Hussmann deli service case today and they told me just the opposite. Set the Thermostat's to 28* discharge air, and set the EPR a few degrees below the evap setpoint so if a stat fails it will freeze and you'll now you have a problem. They also had suction stops not LLS

[John Markl]

In my stores, that particular circuit runs all the service deli stuff....display cases, cheese boat, retarder, and walk-in. no solenoids or EPR at the rack. Everything controlled by t-stat.

It struck me odd, that the original install on the service displays had both lines valved....but then later the LL solenoid removed.....heck, they didn't even bother to remove the coil, just left it dangling there, and of course it's burned up.