what is the cutout setpoint on the pressure control? it's fairly common to see a small increase in pressure on the suction side if the cutout point isn't close to zero. a leaking solenoid valve will most likely cause suction pressure to continue to rise and the unit to repeatedly cycle off and on.

 

Heatermanbob,

The setting is 6PSI (18/12). The "bleed through" is very slow, & as far as "cycling"? It's not doing that. The air bulb stat is pulling the unit down to 37 degrees, which in turn is pulling in the valve, for the pump down. Much of this system is original from 1999, yet, many people have worked on this cooler, & other components of the store, & "Hacked" many repairs. Sporlan Tech is telling me that this valve is for an 8 ton application, & "to big" for the compressor /system. a 3 door walk in, at the same store, had the same size valve on it, but, that system was "Hacked so badly", that it failed, & had to be replaced. This valve is on a 3 evaporator walk in cooler, where I replaced the compressor, failed Contactor, time clock, & one evaporator motor. I told the customer about this valve being over sized, when I had the system down, & installing the correct valve would've been easier. He wanted his cooler going, & said he'd "worry about it later".
My concern is seeing this "steady trickle" in the site glass, "IF", I am to have a 100% closing of the valve.

My customer is from Ethiopia, & on one hand proclaims that "he is poor", & then later speaks of his vacations, private school for his kids, & the amount of credit he can get for opening up a restaurant in the same building. Our agreement is that he gets a discount, based upon my doing ALL of his HVAC/Electrical/Refrigeration/Plumbing & Restaurant equipment, so I want to be sure of dotting all of my "i's & t's". All of this work I did on this cooler, was done by a contract, & specific to the Condenser repairs. Any other work, which is referred to in the contract, such as cleaning all of the coils, adjusting the TX Valves etc., is to be additional.
So, a "small increase in pressure", you consider "Normal"? Does that include new valves also?

 

any liquid or saturated vapor downstream of the solenoid valve is going to boil off and increase pressure once the pressure switch shuts the compressor off. not convinced you have a leaking solenoid valve if it's not continuously increasing pressure and short cycling.

 

Is the valve close to the Evaps,as it should be?

 

Small increase normal, if it is enough to cause it to attempt pumpdown, it might be leaking at the solenoid valve or back into the discharge side thru valves. I would pump it down, isolate the discharge, and make sure the comp cannot restart and watch your low side. A slow leak on the solenoid might also show up as temp diff over it form in to out.

 

I would be concerned if the unit has multiple,3-4 pumpdown's on 1 off cycle with a long line set.Close couple and either the lo pres sw is not set low enough or it's by-passing someplace.Do as buford said and find the cause.

As far as the "customer". Well,That goes without saying bro.We all been there,seen it.Either hold the Hand or fold.

 

If its not cycling , dont worry about it
If SH looks good , fughedaboudit

 

Whelp,..... somehow, when I went to post my reply, I got informed that I didn't have permission to post. Then I saw that I had to log back in. When I went back to post my reply, to the last 5 comments, it was gone!
I don't understand this, cuz, I only went to the coffee pot, & then called the dog in from outside (less than 5 minutes.).
I've got things to do in the Physical world, & I'll have to get back with Ya'll tonite.

Heatrmanbob, Coolperfect, Buford,Mr.kelly, & Snapperhead,.... I appreciate your input.

 

It seems to happen around here.
I accidentally double post because "something" is trying to do "something".
When this happens,I copy my intended post and when it makes up it's mind,paste my original response back in.
Why can I post in AOP with no * ? Can so whatever. Yes I am qualified but no *.

 

Just reread you OP. Bubbling "could" be noncond's as well.Just a thought.

 

Mrkelly, it's not "bubbling", ..., it's a swirling trickle, & the pressure rise is ridiculously very small, the low side gauge actually rises slower than what this "trickle" would suggest.

Coolperfect, the solenoid is approximately 28" away from the middle evaporator.

Buford, will do, when I go back, & the temp rise across the solenoid is 2.8 degrees.

This unit is not short cycling.In fact, I called there yesterday, & talked to the "American help", & he said it's running better than ever. (this store has been open only 2 years, after sitting empty 2 years).

Snapper, it's not, & I'm jus' making observations, & asking questions. My understanding is that these valves are to be "Fully Seated", which it's not doing. If this were a gas valve, it'd be leaking gas into the furnace.I'm analytical in all that I do, whether it be GOD, Family, Country, or my work.

Now, I'm being told to " that I do not have permission to perform this action, & to refresh the page"! I'm logged in, & down to the bottom right, I can see that I have permission. Waassuupp with that? I'll C & P this & re-post it.

 

Snapper, My understanding is that these valves are to be "Fully Seated", which it's not doing. If this were a gas valve, it'd be leaking gas into the furnace

I think you are seeing refrigerant boiling , because if the valve was indeed leaking by - it would be cycling sir

 

The unit is not short-cycling, Sir. :>) This "Trickle" starts shortly after shutting down on the T-stat setting, & the unit is off. The unit is coming back on in response to the walk-in conditions, which averaged 12-18 minutes of shut down time. Liq. Drier has no temperature difference. No frost back. Upon start-up the site glass fills up completely, & stays that way, till the T-stat is satisfied, & the pump down is initiated. After the unit shuts off on the low pressure switch, in about a minute, there's movement in the glass, & then this small trickle begins, with the very small rise in pressure.
Buford, when I go back, I'll follow your recommendations.

 

David i think things are in good shape now, like others have said, if it's not trying to pump down when the box is satisfied in between calls i think your good.

 

I appreciate your advice Buford, & perhaps I'm being to analytical, but, this is another situation that I've never seen before, just like the compressor that I replaced that had power & wouldn't run. Maybe that store needs an Exorcism.

 

If it pumped down and the compressor stayed off for 12-18 minutes, I would not worry.

 

Thanks Mike.

 

I have a good relation with a Catholic Priest.:angel:
That is one of my "sayings" when I encounter "demon's" on a callback.
"Well,If it goes out again,I'm bringing a Priest back with me."

 

LOL! mrkelly, he does make "Service calls"? :bump:

 

I have actually considered it on some unit's. :Faint: