20 Most Recent True 49 cu. ft. / 1388 liter Commercial Freezer GDM-49F-RC Questions & Answers

most freezers have 2 controls. 1 is a defrost terminator and the other is a fan delay. the delay and the defrost terminator can sometimes be a "2 in 1" type switch. you would have to study the wiring diagram. The delay will not let the fans come on untill the evap reaches a preset temperature. take another look at the diagram. It may be that the evap is not getting cold enough. you may have a refrigeration issue.

To me it sounds like, from what I am reading that your compressor may be the root cause if it is short cycling and you changed the thermostat and moved the thermocouple and the problem persists. Was this working fine till recently or did you just aquire the freezer and noticed it is not performing correctly?
Here's the simple procedure I use whenever I run into one that's 'short-cycling' (trying to start, clicking on/off every few seconds, or in some cases, every minute or two).

Basically, using a digital ohmmeter, you pull the compressor's relay and overload off its three terminals, then check the resistance between each of these three pins. Older relays looked a bit different than the solid state ones, but pull off pretty much the same way.

First note the two pins that read the highest resistance. The one that remains is the 'common', to which one end of both the start and main windings connect. (The common's not always the top pin, so you'll want to do this test to be sure) Reading from that common to each of the other two, carefully note each reading. Then measure back across the two with the highest resistance, ignoring the common. That reading should be the exact total of the two individual coil readings, because you're reading through both coils in series now.

If those two sets of readings aren't within about 1/2 ohm of each other, then one of the compressor windings is shorted, and if it runs at all, it'll run hot and usually end up short-cycling on its overload protector. If the windings test OK, but it still won't run, then I connect a test cord and try to run it manually. If I can't start it that way, it's most likely a mechanical problem, most often binding bearings, and the 'bottom line's the same: either the compressor or freezer will have to be replaced.

Did the new thermostat come with an adjustment screw in the back? if so you might want to play with that as that can also cause this issue if it is not set correctly.

You may have a defective thermostat..

Their are no such digrams to tell about the coils and how they run to the compressors

Sounds like to have a defective defrost timer

drain tube runs from dead center of the coil into the back wall and down under the unit where it drains into a pan and is evaporated. Sounds like just a blocked drain tube. The easiest way to clear this is to take the bottom front grill off and look for the drain tube which is typically just strapped to the top of the opening suspended over the pan. Use a wet vac to pull out the sludge or some kind of pressure to blow it back up into the cabinet. Problem with blowing back is that dirt and water are going to blow into the cabinet and/or coil. taking the hose off of the interior coil is difficult and you can break the plastic connector so I don't recommend that to anyone.

What gas is it on? R404a 12 -14 psig

See previous answer, but also check it is defrosting itself 3 times a day

Could be a number of things. It has a thermistor that sits on the evaporator to keep the fan off until it gets cold. It also has a switch above the door that switches the fan on when the door's closed. It could be a loose connection in the wiring, or, lastly, it could be a seized fan

cap tube/ has unit been serviced before/ if you know it has correct charge compressor may have failed easy fix. expansion valve or cap tube maybe another thing to check i always remove entire charge get a good micron reading put exact charge back in if wont pull down comp. likelly

Most all commercial freezers have some sort of fan delay/ defrost termination device. Commonly called a "Klixon" (pronounced clicks-on). It is a device that is attached to the evap. It's function is to terminate the defrost cycle when the evap reaches a certain temp, say about 50 degrees or so, to ensure there is no build up of frost/ ice on the evap. It then allows the compressor to run, and cool the evap down to a reasonable temp., say about 20 degrees, and then let the evap fan come on. It prevents overloading the compressor during a high temp condition, and it also prevents circulating warm air left from the defrost cycle. I believe this device is most likely your problem. With no air circulating, the box will no cool down.. I have seen them burn and/or slhort internally. They can come apart. too. I would look here for that problem. the True manufacturing website does not give alot of info on this piece of equipment, such as a wiring diagram but manuals are available.
Check this out and let me know how it comes out.

Bad fan delay

You have a dead short.