I want [b]your[/b] opinion

[smilies]

O.K, here it is:

a combo system with many cases on one liquid line and L.L.S at each case controlled by temperature, store specs.

Now some of those cases have suction stops controlled by a t-stat, from the manufacturer.

Since the temp in the case is controlled by the L.L.S, do you set the suction stop t-stat to desired temp (sort of like a back-up) or do you set it as low as it goes and let the L.L.S do its job?

[emerson climate tech]

For tightest control cycle both valves together on one t-stat to avoid pumping down between cycles, but close only the LLSV for defrost to force pump-down and promote good oil return periodically.

[NedFlanders]

Are all these cases same type?




You said some cases have SS and LL solinoids?

Service meat cases use SS for temp control ,I can't think of anything else that needs to. I'd use the LL for anything else.

Is one compresser running all this?

I don't like all these stats and solinoids..the suction must be all over the place.

[smilies]

I should have clarified. This is one circuit on one rack.

And yes, these are service cases online with some MDDL and cheese island, and bakery cases, and anything else they wanted on it. Total of 13 cases.

I like the idea to cycle both together since I already have the SS in the cases.

I'm asking because we have no company policy on it, just whatever the start-up tech sets it for. I myself dump the SS to the lowest setting, since the STORE plans call for the LLS to control it, and that's how it's printed on the refrigeration schedule.

As for temp and defrost, COMTROL controls each LLS at the cases.

[refer dude 2479]

Originally posted by NedFlanders



Service meat cases use SS for temp control ,I can't think of anything else that needs to. I'd use the LL for anything else.


I have to agree with Ned. Any type of fixture that has humidity sensitive produce should use the suction stop for the main control. That would be any type of service case, flowers, meat holding bow where meat is unwrapper etc. For all the rest LL Sol val is just fine. Both is overkill. If you must do both use one tstat to control both valves

[smilies]

Well, this chain has taken to putting misting systems in their service cases in order to use the LLS as main control. While it looks real cool when it turns on, it's becoming a frozen case problem since they do not clean these cases, even though the product is pulled at the end of the day.

[refer dude 2479]

suction stop will help with the icing problem too. when the valve closes refrigeration stops right now.coils has to start getting warmer. most case makers require suction stop on gravity cases, which I assume these are

[smilies]

No, the coil is not a problem. The defrost is at night, all night when the case is empty. I'm talking about the pan area, the drain and the pipes there.

[NedFlanders]

Jerry , I know who you work for :D

Float everything on the suction group in the Comtrol and cycle the SS for the service case for temp.

Make Pete C.( Anaheim ) proud

[condenseddave]

I'm with Ned.

[smilies]

Originally posted by NedFlanders
Jerry , I know who you work for :D

Float everything on the suction group in the Comtrol and cycle the SS for the service case for temp.

Make Pete C.( Anaheim ) proud

I'd like to, but at this account we cannot mess with the EMS. Whatever the store prints say is what we have to do. Even though they were modified 9 times during construction and thrice since. I see it as let the stores learn their lesson. The employees are already asking us to change this and change that, but we can't. Oh well.
And I'm not gonna say a thing about this branch.

[NedFlanders]

Hands tied huh?....aint it great..it's like Wal-Mart work(hehe)

[NedFlanders]

Originally posted by condenseddave
I'm with Ned.



You see that? I must be right this time :D

[mccool]

I'm surprised to see both liquid solenoids and suction stop on some or all of the subcircuits. We have similar circuits all using suction stop only, no need for 2 valves, the suction stop best controls temp, defrost and problems with service case icing all in one. The liquid line solenoid is not needed on these kind of multi circuited systems and is a source for more maintenance and leaks. CHING CHING ok I call for LL solenoids everywhere. :)

I Like those Comtrol systems and the assigned suction floats, have 1 store that uses fresh meat as primary float assignment and no epr's or other temp control on that system and it maintains proper temp through the controller using that system as it's setpoint. Works good!

[refer dude 2479]

Let's start a movement. I'm with Ned too.

If you are any good with the word processor you might write up the recommendations and pass them on to your employer to forward to the customer for thier review. If your employer has a relationship with the construction managment team for the store you may be able to empliment some changes in their specs and them go back on all of the other stores and retro the control settings. Could be a big smiley face for you and your employer.


Then again could be a waste of time. Have had it go both ways.