Reply to Thread

I've been working on denny's freezer/fridge drawers for a couple years now. always a pain in the arse. The one im working on currantly has 3 compressors on the roof. 2 of the compressors are running multiple fridge drawers. About 4 a peice. The other compressoor is running just one freezer drawer. All 3 compressors have liquid acumilators. the freezer drawer system has a suction line acumilator also. They all have pressure controls to cut out on pressure drop. All the fan coil's have silinoids. the fridge drawers have t-stats inside the drawer units. the freezer draw has no t-stat and is controlled by the pressure control that shuts the copressor off when the unit dropes to a pressure on the low side that correlates to the temp inside the freezer. They all have defrost controls.

I had the freezer drawer down to 5* f threw last fall and winter. now that it is warming up outside it is having problems again. started by cleaning the coils outside that were filthy. temp still not low enough. now im back to counting turns on the expantion valve and playin with the charge. I hate these units.

I hate set ups on singles with multiple loads and then not provide anything for capacity reduction.

The ones I installed for them did not have EPR valves. They also used transflow blowers not standard fans. Agree that w/ epr they would have worked much better but I was not the engineer and they wanted to keep cost low, didn't seem to consider future service cost.

Is your discharge line Hot? If not climb in the cases and try to figure out which valve is overfeeding. Also check out the evap fan blades. Alot of guys end up throwing a little 3incher on when it needs a 5.5".

Originally Posted by VTP99

Hackmaster,
The EPR is a evaporator pressure regulator. If you have them on the suction lines there will be a dust cap you remove to access a allen screw. Adjusting will regulate the evaporator outlet pressure.

I dumped the 404 that was in it and pulled a good vacume and cleared the sight glass with new refrigerant. Im still getting an iced up line including the compressor but at least ive eliminated moisture being a problem. Im running 25 on the low side and 250 on the high side. Ive got a 10 degree line at the evaporator outlet and its frosted over the whole line. Still I cannot get the box temp below 30 in any of the 3 evaps. Im down to either having to adjust these expansion valves or finding this EPR valve you are speaking of. Do these types of valves go out of adjustments often??? Do you know if all systems of this type has this valve installed on them? I could not go further with this today because I had to go to a different restaurant and replace a condensing unit on another drawer system...lucky me.

Originally Posted by hackmaster

What is an EPR? I havent looked up in the drop ceiling yet.

Should be mounted in or near the case.

Looks like this

Hackmaster,
The EPR is a evaporator pressure regulator. If you have them on the suction lines there will be a dust cap you remove to access a allen screw. Adjusting will regulate the evaporator outlet pressure.

Originally Posted by hackmaster

Im in the upstate in Greenville. I use to do a good bit of refrigeration but in the past 5 years its been mainly HVAC until I got thrown into all these Dennys and in all honesty its a god awful mess...not a good situation for me to get acclimated again. It seems every call I get is some kind of weird freaky thing going on. In this particular Dennys both defrost timers are open and coated with egg, sausage grease you name it but the timer to this 404 drawer is still working. I felt today it may be over charged so I reclaimed refrigerant just until I got bubbles in the sight glass and and let it run till it equalized. Now Ive got a frosted up line but at least the compressor is no longer frozen. Ive got 25 pounds on the low side and 225 on my high side. When I check temp on the line at the compressor my temperature is swinging wildly from 23* then within minutes it will go down to 6* but the low side pressure remains constant at 25. Im thinking maybe moisture or a bad expansion valve on one of the evaps but im getting frustrated. Climbing up and down the side of this building is wearing on me. Im considering just dumping the system refrigerant and evacuating then starting over just to rule out contaminants. The gaskets on the drawers seem to be ok and they are closed. The real frustrating part of this whole thing is while im sitting there scratching my head over this it appears the condensing unit for the ice machine is now malfunctioning even as im standing there. The drawer set up just seems to me to be a very bad idea considering who is opening and closing them. Most of these drawers are beat all to hell.

Are all txv sensing bulbs installed properly? On tight, insulated, and so on. The only other advice I can offer is do not get frustrated.

Originally Posted by VTP99

Do you have EPR,s on the suction lines of each evaporator ? The Denny's I've worked on had them on the backside of the cook line wall up in the drop ceiling. Suction lines continued on to the roof top condenser which contained three compressors.

What is an EPR? I havent looked up in the drop ceiling yet.

Do you have EPR,s on the suction lines of each evaporator ? The Denny's I've worked on had them on the backside of the cook line wall up in the drop ceiling. Suction lines continued on to the roof top condenser which contained three compressors.

Originally Posted by VTP99

Problem i have found with these is cooks don't close drawers half the time and so the evaporators freeze up. Or the drawer seals are not sealing because of misaligned drawers. Did you check your defrost clock when you arrived ? It may have just came out of defrost before you got there giving you a false indication of the coil. 320psi on the high side is to high unless its say 80* outside or you have a restriction. Is your outside coil clean ? What kind of head pressure control ? Fan cycling ? 14*= 50psi-35psi=15* superheat is high. Should be around 4-6* @ evaporator. Were just getting started.

Although the defrost timer is in poor condition and coated with all sorts of grease and other renderings as its located right under the dripping cook tops it is working and it was not just coming out of defrost. The drawers do seem to seal ok on this particular system so I dont feel its drawing in any excess air to the point of causing this sudden problem. It does have a fan cycling control that cuts out at 150 and cuts in at 250. It had a malfunctioning duel pressure control that I replaced. Outside ambient is 70. These drawers are deep with the evaps deep inside them at the back and its a choir just to squeeze my big butt up side the hole to try and get any kind of temp of the line at the evap. Imagine doing that while you have 3 cooks stepping all over you. So Ive been taking my temps at the line at the compressor. At the compressor now I have a low side line temp swinging from 23* all the way back down to 6* then back up again all withing minutes and its continuous after 2 hour run time. My low side pressure is now 25 and high side is maintaining steady at 225. Box temp can get down to about 28* and thats about it. Coil on condenser is clean and evap coils are clean.

Originally Posted by codgy

Where are you in sc , I put some of these in for dennys back 15-18 years ago and yes they are godawful to service.

Im in the upstate in Greenville. I use to do a good bit of refrigeration but in the past 5 years its been mainly HVAC until I got thrown into all these Dennys and in all honesty its a god awful mess...not a good situation for me to get acclimated again. It seems every call I get is some kind of weird freaky thing going on. In this particular Dennys both defrost timers are open and coated with egg, sausage grease you name it but the timer to this 404 drawer is still working. I felt today it may be over charged so I reclaimed refrigerant just until I got bubbles in the sight glass and and let it run till it equalized. Now Ive got a frosted up line but at least the compressor is no longer frozen. Ive got 25 pounds on the low side and 225 on my high side. When I check temp on the line at the compressor my temperature is swinging wildly from 23* then within minutes it will go down to 6* but the low side pressure remains constant at 25. Im thinking maybe moisture or a bad expansion valve on one of the evaps but im getting frustrated. Climbing up and down the side of this building is wearing on me. Im considering just dumping the system refrigerant and evacuating then starting over just to rule out contaminants. The gaskets on the drawers seem to be ok and they are closed. The real frustrating part of this whole thing is while im sitting there scratching my head over this it appears the condensing unit for the ice machine is now malfunctioning even as im standing there. The drawer set up just seems to me to be a very bad idea considering who is opening and closing them. Most of these drawers are beat all to hell.

Where are you in sc , I put some of these in for dennys back 15-18 years ago and yes they are godawful to service.

Moisture in system.

NO ice on the coils but ice on the compressor and suction line! Liquid in the suction line! If you have 3 seperate evaporators, you hopefully have 3 liquid line solenoids and thermostats. I think 1 of the 3 t.x.v.s is overfeeding. Try to cycle 1 thermostat off at a time, when the suction pressure drops and the frost goes away you found the overfeeding t.x.v.

+1 on the drawers not being closed..
door gaskets bad..
drawers being diamonded due to being slammed shut w knees...
those line cooks can be the root of the problem..
id check and see if they are shut when you get there next time....

we had one dennys the walk in would always freeze up...
found the door open to walkin most times i got there...(they were in such a hurry they couldnt take the time to use the door thus leave it open )
installed a baseball bat closer on it..
strangely after that the freezing up stopped...

Problem i have found with these is cooks don't close drawers half the time and so the evaporators freeze up. Or the drawer seals are not sealing because of misaligned drawers. Did you check your defrost clock when you arrived ? It may have just came out of defrost before you got there giving you a false indication of the coil. 320psi on the high side is to high unless its say 80* outside or you have a restriction. Is your outside coil clean ? What kind of head pressure control ? Fan cycling ? 14*= 50psi-35psi=15* superheat is high. Should be around 4-6* @ evaporator. Were just getting started.

R404 freezer drawers under cooktop

Hi guys hope yall can help me out. These drawers are in a Dennys restaurant under their cook tops. Condensing unit is on the roof and it runs 3 different small evaporators with 2 drawers each one of top of the other under the cooktop. Not really sure how common these are but this is the problem. When I got there all 2 of the evaporators cooling the box to about 34* and one of them cooling at 27* box temperature. On the roof the line is all frozen up including about half of the compressor. The evaporators have some frost on them but not blocked and fans are turning at the evaps. Ive got a clear site glass my low side pressure is 35 and high side is 320. Ive got a 14 degree line temp at the compressor. These evaporators are small and very difficult to get to with no service port fittings. Anyone who can help me out? Im primarily an HVAC guy who was thrown into these restaurants and Im a bit rusty. These drawers are low temp and not med temp.