Help identifying thermal fuse or sensor on commercial freezer please.

Working on a commercial reach in freezer that was icing up. Took the cover off the evaporator and it has 3 heaters, evaporator heater, drip tray heater, and drain tube heater. Only the drain tube heater was working. Tracked it down to this little piece that was attached to the heat tube on the bottom of the evaporator. I don't have a full wiring diagram so can't verify but pretty sure this is one of the things that will turn the heater on the evaporator coil on and off. I was going to jumper it to see if the heaters would come on but without having a wiring diagram and knowing for sure I didn't want to cause any issues. Figure I would get a replacement since it's shot and see how a new one works.

Problem is this is a berg EDRF-72 which I'm finding out is just a cheap throw away piece. I can't find anything online for parts or diagrams. I contacted restaurant equippers who sell them and they said this model is discontinued and they wouldn't have any parts and may be a chance of being to order them if I call tech support but didn't sound promising. This thing isn't that old and is working good besides the evaporator icing up because the heaters not working and not able to defrost it like it should.

Anybody with more smarts then me be able to tell me what this part is and if I may be able to get some type of universal one to wire in? Seems like it's some sort of limit switch or thermal fuse that breaks connection when the defrost heater gets too hot. Not sure if they come in different temp settings or how to figure out which temp cut out would be needed for a freezer defroster. I can't find anything that looks exactly like it doing a google search but have found things like this, https://www.sunfull-hanbec.com/defr...c-thermostat-thermal-fuse-assembly-3-product/, that look similar.

Hate to junk a perfectly good freezer that costs several grand to replace because of a simple little sensor so hoping to find a universal replacement to keep it working.

I'll upload some pictures from my phone in a minute.

Is there any markings on it? under the tape maybe?

dscheidt said:

Is there any markings on it? under the tape maybe?

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I cut the sleeve off and don't see any markings but it's crusty so even if there was some I can't read them. Pretty sure this is just a safety "fuse" or sensor that is attached to the heating tube on the bottom of the evaporator to shut the heater down if it gets too hot. I'm guessing most of them are probably set to open around the same temp so would think any one I find online would work. But would like to learn what this exactly is and then learn more about it before just blindly slapping parts in and messing something up.

dscheidt said:

Is there any markings on it? under the tape maybe?

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After typing I got a scotchbrite pad and tried scrubbing some of the crud off of it. The plating on the top is long gone but on the metal flaps that are folded over I found some markings, on one side it says MEKEYS. I typed that into google and a bunch of electrical components came up and one was from digikey showing something that looks exactly like this, https://www.digikey.com/en/products...7IeGqtlmkV_NAmKKmoBNPApNr9QnQc-xoC2BsQAvD_BwE. Thanks for making me look a little harder for some markings. I'm thinking this has to be the same thing.

Looks like they come in different temp settings if you scroll to the bottom of this page, https://www.digikey.com/en/products/filter/industrial-sensors/thermostats-mechanical-industrial/1072?s=N4IgrCBcoA5QjAGhDOkBMYC+Wg. Wonder how I pick the temp I need for this without any markings.

Maybe ask them

Headquarters​

Cantherm
8415 Mountain Sights Avenue
Montreal (Quebec), H4P 2B8, Canada

Toll Free: 1-800-561-7207
Tel: (514) 739-3274
Fax: (514) 739-2902

Email: [email protected]

Could it be a heater safety limit switch? Opens if it gets too hot (or defrost heater gets stuck on) to open heater circuit closes when temp comes down to some threshold. See video beginning about 2:40 for more info. The device in video opens at 75 degrees F and closes at 40 degrees F. That may give range to work with.

cgrutt said:

Could it be a heater safety limit switch? Opens if it gets too hot (or defrost heater gets stuck on) to open heater circuit closes when temp comes down to some threshold. See video beginning about 2:40 for more info. The device in video opens at 75 degrees F and closes at 40 degrees F. That may give range to work with.

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I do believe that is what it is, to keep the evaporator from getting to hot. During the defrost cycle the heaters get energized and if the heater gets over whatever temp this sensor is rated for it kills power to the heater until it cools down enough. Trying to find what temp these usually are rated for on google tonight I was seeing temps all over the place. Some saying up to 500 degrees but most saying hot enough that you can't touch them with your hand. I ordered a handful of different temp sensors from digikey to get them coming since they were only 1.55 each. Think the lowest rating was 130 degrees opening temp. I'm going to keep trying to find a temp rating but info out there is pretty limited. But at least I'll have a selection of different temp ratings on the way for when I do figure out the correct rating.

Can't icing up also be just a bad door seal?
I'm all into saving this commercial freezer. I saved a nice commercial refrigerator but skipped the DIY part. A local 1 guy appliance repair guy figured it out right away. Since then I had him order a door seal to install when I had him over to fix a sensor in our gas oven/cook top.
I usually hang out with him and in our conversations I brought up the new stuff (residential) compared to commercial and it's ease of keeping it running virtually forever.

jack stand said:

Can't icing up also be just a bad door seal?
I'm all into saving this commercial freezer. I saved a nice commercial refrigerator but skipped the DIY part. A local 1 guy appliance repair guy figured it out right away. Since then I had him order a door seal to install when I had him over to fix a sensor in our gas oven/cook top.
I usually hang out with him and in our conversations I brought up the new stuff (residential) compared to commercial and it's ease of keeping it running virtually forever.

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Icing up can be caused by a few different things, door seals, low refrigerant, poor air circulation from bad fans or too much food inside not allowing circulation of the air, bad heaters or heater controls, etc. I didn't see anything obvious with the door seals, they took some pulling to open the door and didn't see any damage or gaps. So moved on to the defrost system and found the bad part.

pcmeiners said:

https://www.hctemp.com/18AMA-motor-thermal-protector-bimetal-thermal-protector-pd94611226.html

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They also list different ones with different opening temp ratings. Are you saying the one you linked is the correct opening temp for something like this?

"Are you saying the one you linked is the correct opening temp for something like this?"
No, you need to do further research.

pcmeiners said:

"Are you saying the one you linked is the correct opening temp for something like this?"
No, you need to do further research.

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Ok I found the exact type that was in there and linked to digikey in above post but still need to figure out what opening temp they are supposed to be. Thanks

signcrafter said:

Ok I found the exact type that was in there and linked to digikey in above post but still need to figure out what opening temp they are supposed to be. Thanks

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Do it the easy way. Just call the manufacturer at the info I provided. They will know what application is best. If they don't, they may be able to tell you how to now which model device you have. Color of it, thickness. dimensions etc..

BurtEggley said:

Do it the easy way. Just call the manufacturer at the info I provided. They will know what application is best. If they don't, they may be able to tell you how to now which model device you have. Color of it, thickness. dimensions etc..

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Guess I didn't put 2 and 2 together yesterday when you posted the company info, that it was manufacturer of the part I linked to on digikey. I went to their website but didn't see the same type of thermistor I need so I went back to googling. I will contact them and see if they can help me with what temp rating I may need.

Thanks for the lead

signcrafter said:

Guess I didn't put 2 and 2 together yesterday when you posted the company info, that it was manufacturer of the part I linked to on digikey. I went to their website but didn't see the same type of thermistor I need so I went back to googling. I will contact them and see if they can help me with what temp rating I may need.

Thanks for the lead

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if they can't help let us know and we will keep searching on it. They have to put some kind of mark on their products, or know what other manufacturers buying from them are ordering for.

Berg shows that Berg 72 unit pulls 14.5 amps if it is material. Their number 877-693-3372. They may not have the part number but it is worth a long shot if the manufacturer of the part can't help. The PDF I got of their units is at https://www.bergrefrigeration.com/wp-content/uploads/2018/12/751823.pdf

I did some additional sleuthing for you. Archive.org shows some older web pages showing the warranty is provided by Argus Commercial Inc. The limited warranty says that if it is used residentially the warranty is null and void. The contact info was Argus, 13195 NW 147th Ave., Miami FL phone of 330-477-1680. https://www.argusrefrigeration.com/ BUT Google maps in 2026 shows that address as nothing but open farm fields and a water preserve with nothing nearby. It is essentially the same webpage as the berg one but different names on the images etc.. A google of the phone shows nothing. InterNIC shows that argus refrigeration is registered to a kevinm "at" equippers.com. Substitute @ for "at". 1-614-464-0505. 635 W BROAD ST, COLUMBUS, OH, 43215-2711. Equippers.com is Restaurant Equippers Warehouse Stores.

I made some changes on the last post. Good luck.

BurtEggley said:

if they can't help let us know and we will keep searching on it. They have to put some kind of mark on their products, or know what other manufacturers buying from them are ordering for.

Berg shows that Berg 72 unit pulls 14.5 amps if it is material. Their number 877-693-3372. They may not have the part number but it is worth a long shot if the manufacturer of the part can't help. The PDF I got of their units is at https://www.bergrefrigeration.com/wp-content/uploads/2018/12/751823.pdf

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The one I took out of the freezer is marked MEKEYS so don't think it's the same manufacturer as cantherm, but look similar. The one I have is in rough shape so don't think I'm going to be able to find any marking to show a temp value. I would have thought I would have been able to find out googling how hot you want the heater to get when in defrost mode but haven't been able to find any info on that. The heater this controls is the one attached to the evaporator and this sensor is attached to the heater, heater is just a tube style. I really would have thought a temp range for evap defrost heaters would be out there for testing purposes so you can check if it's opening at the correct temp, but seems not. I doubt it needs to be an exact temp match but needs to be somewhat close and the choices range from 100 to 500 for the sensors I found.

Yes this berg company is just a cheap company that probably services their stuff under warranty and then considers it a throw away item. I couldn't find any parts diagrams or parts sites like you can for most appliances. Crazy because even though they are cheaply made they are still an expensive appliance.

I just went off your links. Digikey shows the manufacture of the parts in your link to be Cantherm. When I Google it, nothing comes up of value. Google Lens finds nothing either of value. Maybe the InterNIC information will lead you to someone who can tell you what the part is or lead you to a schematic. That said , if you don't know the specs on the part, are you even sure it is the cause of your problem?

BTW if it is MEKEVS not MEKEYS https://www.hctemp.com/18AMA-motor-thermal-protector-bimetal-thermal-protector-pd94611226.html

the parent company http://www.jsmeikai.com.cn/en/list.asp?classid=6 (slow to load so be patient. email them a photo, give them the application and see if they respond. Longshot but I would try. [email protected]