barker case problems

[neumonic]

Just installed 4 barker deli cases and having trouble making temp and running out of ideas.

Case model PF-8 and PF-6
The txv is frosting after the valve and the frost doesn't make it through the first pass. So what I did at first was open the valve up a bit to get more flow with no result.

The valve in the 8ft case is a SBQE with AA cartridge and the 6ft case has a SQ with a 2 cartridge. The valves came with 404 a power element and the rack is running 507.

I verified all cartriges were correct from the factory.

So I had no luck opening the valve so I installed 507 power elements on with no change.

I checked the spec sheet and case is supposed to have 200fpm DA which is does.

Also Added a sightglass and access port in the liquid line.

Full column at the txv and 180psi liquid pressure.

At case liquid 180psi
78* F liquid line temp
SC around 3*F
Suction 55psi
55*F suction temp
SH 37*F

At rack

Liquid 180psi
Suction 54psi

I currently have one txv all the way open with little to no change.

Any ideas? Thanks in advance

[ammoniadog]

That does sound like a strange problem you have. The only ideas I can come up with is if these are open display cases, make sure there isn't a heating diffuser or something blowing into them. From what you describe, though, it sounds like you are on the right track with suspecting the TXV. Maybe it is partially clogged up with something, or it is just plain bad.

[Phase Loss]

I'd put in SBQE-A valves on both of them. I think your valves are undersized

[neumonic]

There is 4 cases in this island setup and none are making temp. I have one txv wide open with no change. I checked the screens yesterday and cleaned them. Double checked them today and clean as a whistle. I also put some poly oin the case as these are open display cases to try and see if that helps. The case dropped a couple degris in like 20 minutes which was very minimal change. Just seems very odd to me none will drop in temp. I aslo changed a valve out with a complete new body , cartridge and element . I'm really running out of ideas.

EPR at rack set for 55psi R507

[Phase Loss]

I think the "A" cartridge is your key

You have liquid
You have SST
You have airflow

but you have starving.

[neumonic]

The 8ft case is 740 btu\ft so 5940 btu total.
The 6ft case is 4440 btu total.
So you would think the 6ft case with the "2" cartrige in it would be sufficient.
The 8ft should have the "A" cartrige in it I agree , just baffles me that the 6ft case is having the same problem.

[Phase Loss]

Everything I see shows the PF series at 1500 Btu/ft at 18* SST

PF-6: 9000 Btu/h
PF-8: 12000 Btu/h

[icemeister]

The AA cartridge is definitely undersized. Sporlan lists them at a nominal 1/4-1/3 ton with R404A/R507. The A cartridge should work fine.

As for the QC-2 cartridge on the 6 ft case, that's rated at 1/2 ton with R404A/R507 so it should work, but I have had instances where going up to the next size worked.

[Phase Loss]

you did a fantastic job troubleshooting and providing the information required

[neumonic]

Thanks for the help boys turns out the glass wasn't as full as I thought it was. Had a coworker come help me out. Added some gas and adjusted the hold back and receiver valve as well. They just converted the store from comtrol to micrthermo so now sensors and leak detectors are actually monitored. Found a couple leaks at the rack in the process. I feel like a jackass but at least we got this solved. Receiver guage was reading 10 percent so that thing must be hooped. Still may have to change the cartriges ill see how she's doing on monday.