Replysorry some info that was forgotten
R-22 case with clear site glass running at 44psi couldnt get liquid pressure due to leaking stem on receiver..... which is going to be replaced in the morning
Professional Member
call came in as top shelf temping too high. other tech was out said it was because there was a register in ceiling above it and blowing heat down on it, recommended moving duct. I went there the case was at 50. found t stat set for 35 and open. turned down, cycled on.
did find that the fan motor closest to sensing bulb seized up causing that part of coil to get colder with no air movement over it causing stat to cycle off. Replaced motor and cleaned out returns and even pulled case apart to clean off the deflectors going up the center. cycled case came down to temp several times. had mgr put product in and would return in morning.
returned this morning and case at 37-38 but mgr says top tier is still temping at 41-48.
I did not get the case model, bad me, but it is very similar to the RIN3 case
Anything Im missing? any suggestions to get more air flow up to the top level.
BTW there are 4 motors @ 12 watts ea.
Thanks guys
Professional Member
sorry some info that was forgotten
R-22 case with clear site glass running at 44psi couldnt get liquid pressure due to leaking stem on receiver..... which is going to be replaced in the morning
Professional Member
Can you somehow cover or close off the air duct that is blowing hot air onto the top shelf? And let them try it for another day? Just because the other tech missed the fan motor doesn't mean he's wrong about the air duct.
Professional Member*
I have had some heater vent problems in cases but it seems it only affected old cases with missing honeycomb at the top. Island "coffin" cases seem really sensitive to heater air.
Professional Member
he disconnected the duct. and i relocated it down 4 feet or so. nothing blowing down on the case at this time
Professional Member*
Did you temp the top shelf high? I would probably put a logger in the case and inquire as to how he was temping it. If he uses an IR gun they can read bad wrong on shiny deli meat type packaging. If all your fans are good, coil isn't freezing, and the back is clear, you should have good airflow.Originally Posted by mpr73
Professional Member
Your case is too friggen warm
Set it down to 32 supply air or so.
While you're at it, make CERTAIN that the product stocked is cold enough (below 35F)
If it isn't you're BOTH wasting your time.
Professional Member
She was reading off of the dial thermometers that the store puts in. Not the most accurate but that is what they use. I placed my thermometer on the top shelf near the " column" or center part where the air comes up. I was reading 31. but as you move forward it is temping at 41, which is where they are leaving their thermometer. the top shelf is also noticeably warmer than the middle and low shelf, but of course the surface area for cool air to escape is twice the size of the upper
Professional Member
i have case set down to 28 or so on the stat to hold a mid 30 reading and i re stocked the case with product from the walk in at is at temp
Professional Member*
I usually run deli at about 32 which keeps me between their mandatory 35-41 range as long as they dont pack the shelves to tight.
Professional Member
OK. Since you don't have a model number, tell me more about this case.
Describe it to me.
Multi-deck deli describes a LOT of different cases.
Is it a high-back case with 4 or 5 shelves? An island type case with 2-3 shelves?
I need some more details to help you.
While you're at it, try to remember the defrost schedule.
Did you check SH?
Professional Member
Not trying to be a jerk, but did you VERIFY that?
If not, then it wasn't at temp.
Professional Member
island style with 3 total levels. defrosts 6 times a day for 30 mins. I arrived on site 2 hours after the last defrost. and the clock was set fro the proper time.
defrosts at 4, 8, 12 a/p
the case is a hussman and very closely resembles the RI3N model
I did check the supply temp getting down to 29-30 and middle and low shelf were at 35-36. Product came from the WIC which was also at 35
Professional Member
First off, I'm going to say too much defrost.
A case like that will do fine with 4 a day, although you might need to stretch them out to 35 minutes or so.
Those can be a royal pain to get to hold temp.
You MUST cover all of the bases. Get your superheat down, your suction pressure is a bit high for a case like that. I'd like to see an evap down closer to 15-18 rather than 21.
Regular Guest
Did you check the honeycombs themselves? They can get a nice blanket of crap on top of them that will impede airflow quite a bit. I'd think the week holes in the back of the case may be able to keep the lower shelves at temp? Maybe?
Professional Member
Call hussmann and get case specs
SDC/Educational/Membership Committee*
Here's the case specs for the RIN3:
If the case in question is a different model, go to their search page here and enter the case model you have.
The RIN3 calls for a 20ºF evap temp and 27ºF discharge air with 4 defrosts/day, time terminated at 20 minutes.
Verify your store conditions are at or below 75ºFdb/55%RH.
Also, the shelf sizing and load limits are critical on these cases.
Professional Member
We recently removed one of these cases because it would not hold temp on the ends.
I agree with jp. Reduce the defrosts to 4x a day. 30min duration is plenty.
As icemeister indicated, shelf sizing/placement and load limits are very critical in these island cases.
Professional Member
If you believe this case to be a Hussmann "RI" island case, the supply air spec is 26 - 27. In addition, there are several supply air metering plates inside the case that get plugged solid and need cleaned.
Also, the defrost spec is 6 times (every 4 hours) / day for 20 minutes. I set the duration for 25 minutes given the region I am in. It is not "too much" defrost if the case is set down to the proper supply air temp and it builds the expected frost load on the coils.
Last edited by thefreezerguy; 01-31-2012 at 01:55 AM.
"Don't wish it were easier, wish you were better"
Professional Member
x2. These cases plug up with dirt faster than any other case in a supermarket. There is a horizontal baffle mounted in the 'tower' the same height as the pans and I would bet money it's plugged solid. You will need to remove all the bottom product and wash it out with a hose. A velometer is a must-have tool for working on cases.
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