Question about True 49 cu. ft. / 1388 liter Commercial Freezer GDIM-49NT

3 Answers

Normal Operating pressure for true 2 door Freezer R404A Room Under 80 degrees F Box at -10 degrees F

Posted by on

Ad

3 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • True Master
  • 1,266 Answers

The pressures depend, somewhat, on the expansion device,i.e. a TXV or Cap Tube. Take a pressure reading, then convert it to a temperature. The evap temp should be right at 10 colder than the box temp. Remember, heat flows to cold so the evap has to "Lead the Load" in order to cool. In many cases, the condensing pressure is usually ambient temp, plus 30, then convert to a pressure. These are general accepted practices that have been used for many years.

Hope this helps

Posted on Jul 12, 2009

  • CB COOLING Jul 18, 2011

    Why does true use a cpr valve? They seem to be overkill.

    Chris

×

Ad
  • Level 1:

    An expert who has achieved level 1.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

The proper operational pressure on the high side is 450 psig and on low is 200 psig for R-404A

Posted on Feb 14, 2010

Ad
  • Level 1:

    An expert who has achieved level 1.

    New Friend:

    An expert that has 1 follower.

  • Contributor
  • 2 Answers

Not overload the compressor with liquid refrigerant and to help the compressor run below it's designed LRA.

Posted on Jan 21, 2014

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

True T-49 refrigerator/freezer temperature calibration


Contact the manufacture, it is most likely going to be covered under warranty. If the knob is not removable, (check for a set screw on the side of the knob it will take a small allen wrench) Then the thermostat (temp controller) will need to be replaced, if it isn't a style that you can calibrate.

Jan 30, 2014 | True Refrigeration True T-49 2 Door Bottom...

1 Answer

What should the iowside pressure be on freezer went the inside temp. is 0 degree?


Depends what freon you are using.......... For R12 6 to10 PSI
For R502 25 to 30 About the same for R404A

Feb 01, 2011 | Frigidaire Freezers

1 Answer

What is the normal operational pressure in lo/hi side at the compressor of commercial freezer like dispaly case, reach in cabinet or other any low temp refrigeration uses 502 or408A/404a. is there any rule...


why yes there is. Generally speaking, the head pressure should be around the "ambient +30" rule.
That is, measure the entering air temp to the condenser, say 75 degrees. Now add 30 to that and get 105 degrees. Look at a P/T chart and see what the pressure is for that temp which is about 253 for R-404-A.
The evap on a freezer leads the load so, as a general rule, the evap temp is going to be around minus 10 degrees to get a 0 degree box. Coolers are different. So, the pressure for a minus 10 evap is around 25 or so. But the unit has to be close to operating temp. If the box is warm, naturally the pressure is higher. And what influences the pressure is whether or not it's a TXV or a cap tube system.
If a TXV and no receiver, charge by subcooling. If a receiver, fill by sight glass. If Cap tube, charge by superheat.
Hope that answers your question.

Oct 03, 2010 | True 49 cu. ft. / 1388 liter Commercial...

1 Answer

True t-49 Freezer not getting below 10 degrees


is his garage as hot as yours?
Be sure the condenser coil is real clean. Best place to start. Freon levels, door seals are another place to look.
Let me know if I can help any further.

Jun 26, 2010 | True 52 cu. ft. / 1472 liter Commercial...

1 Answer

Evaporator unit keeps on building ice. question what is the nornal operating pressure on low side and on the high side for truee freezer using 404 refrigerant


I'll try to give you the "Readers Digest" version.
First, make sure there is no ice build up on the evap. Light frost is O.K. as long as it does not effect air flow. (Very Important). All fans need to be running. Again, an air flow thing. There should be some product in the box but not too close to the evap. Again, an air flow thing.
The expansion device can effect your pressures to some degree i.e. Cap tube vs. TXV.
As a general rule of thumb, which I use almost everyday when it comes to pressures:
Low side is based on the temp difference between evap temp and condition space in the box. In freezers, it is almost always 10 degrees. If the box is 0 degrees then the evap needs to be at a minus 10 degrees. That is a pressure for R-404A of 24.5 psi. This only holds true when the temp in the box is approching set temp. I would say, about +10 degrees. 0 Degrees for the evap for R-404A is 33.5 psi.
High side should be ambient temp +30 degrees and then convert to a pressure for the refrigerant.
Example: 75 degrees in the room, +30 degrees equals 105 degrees. Now 105 degrees converted to a R-404A pressure is 253 psi. This will get you very close to the desired high side pressure.
I would look at low side first to see if it is within reason. Don't let the high side get too high. Increases the compression ratio and overworks the compressor.
Your icing problem could be a defrost issue and not a refrigerant charge issue.

Good Luck and hope this gets you started.

Apr 07, 2009 | True 49 cu. ft. / 1388 liter Commercial...

1 Answer

Errattic temperatures in Freezer


Check out "victory-refrig.com" for manuals, diagrams, etc.
Cap tube systems are "critical charge systems". Can be difficult to get right. You did not mention pressures that you had. The split on the evap vs.box temp is almost always 10 degrees for freezers. If you want a -10 box, your evap needs to be -20. As a general rule of thumb, you want the high side to be "ambient +30". This seems to work most every time. Your problem might be operations related. Them leaving the door open alot and so on. It could also be a problem with the evap fan or the control to it. It could also be that since there had been a problem with the unit, they are now constantly checking it. Could be checking during a defrost cycle. When your box is at 0 degrees, your pressure should be about a -10 and no less that a -15 degree for the evap. You may have to babysit this thing and see how far it will pull down. You may have a weak compressor. Also, I have had many Hobart freezers fail due to dirty condensers. This causes the oil in cap tube systems to gel and clog up the cap tubes. The only fix is replacing the cap tube. There are alot of variables here so be patient, it's not going to be a quick fix. One last thing, since R404A can fractionate, you really need to pull the charge out and weigh in the correct charge with virgin refrigerant. This will eliminate 2 things. 1, it will ensure the correct amount of refrigerant and, 2 no chance of having a poor mixture of refrigerant in the system causing inconsistant readings and performance.
Hope this helps. And remember, cap tube systems are performance measured by the amount of superheat just prior to the unit making temp and cutting off.

Jan 07, 2009 | Victory Commercial Freezer VSF-3

1 Answer

UP RIGHT FRIGIDAIRE FREEZER AUTO DEFROST 11CF I THINK


This could be normal for the summer. This is the right temp to keep it at. Some units are meant to run 80 - 90 % of the time. Turn it all the way up and check the temp. Most units when working properly can get below 0. Check the condensor underneath for dirt and to see if the fan is running under there. (smaller units don't have anything underneath) Some have coils in the rear and the smallest units just use the sides of the cabinet to disperse the heat. Check the gasket see if its sealing properly or maybe the door is warped and not closing at the bottom.

Jun 28, 2008 | Frigidaire 11.6 cu. ft. / 328 liter...

1 Answer

Normal operating pressures


Normal operating pressures will change as the freezer reaches the selected temperatures on the inside. Normals of minus 14 degrees on the inside would be around minus 4 psi on the suction and 150 pis on discharge. Now checking the pressure will require a set of guages that have been purged with the same freon before connecting with the suction line on freezer. If not purged the suction line will draw outside air into the system and cause freezing of air and moisture inside the capillary tube rendering the freezer inoperative, Hope this helps, Sea Breeze

Nov 01, 2007 | Freezers

Not finding what you are looking for?
True 49 cu. ft. / 1388 liter Commercial Freezer GDIM-49NT Logo

4,085 people viewed this question

Ask a Question

Usually answered in minutes!

Top True Freezers Experts

Dennis Boxerman

Level 3 Expert

1266 Answers

John Tripp
John Tripp

Level 3 Expert

4655 Answers

christian nielsen

Level 3 Expert

358 Answers

Are you a True Freezer Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...