Refrigerators not Working

[argus1]

Usually 10% is a huge issue for most loads. I was trying to get details, which worked…. He responded with accurate info which points to the rectifier being bad…

but it’s still odd both went back the same time, but that’s why it’s pointing to

Yes, I agree it is odd that both went out the same time. I did measure 120V coming into the controller by removing the L and N wires at the top of the controller.

 

[km1125]

The cockpit refrigerator is a Dometic CRX-1050 and the cabin refrigerator is a CRX-1080.

Both units use a Danfoss 101N0500`controller. I confirmed that both units will work on battery power if the 110 AC cord is disconnected. When the AC cord in is connected, both units will stop and run again when the AC cord is connected. I also confirmed with a multimeter that both units have 110/120V going to the controller board.

Now I am under the impression that the Danfoss 101N0500 controller itself is bad on both units. Not sure how to test the controller to make sure.

This still confuses me, if indeed it is the actual cord being connected and there is NO voltage on it. Is it possible that the L and N terminals are reversed (or there's reverse polarity on the incoming circuit) and that is causing some type of a fault within the controller?? That's the only way I could see connecting the cord with no power on it would have an effect on the controller.

Also, ran across a couple things of interest:

The spec for that controller (101N0500), show it accepting an AC voltage of 85 to 265:

And this section of text in the specs. Indicates a time delay when switching from AC to DC but not when switching back from DC to AC. Take this into account as you're doing your troubleshooting

 

[argus1]

This still confuses me, if indeed it is the actual cord being connected and there is NO voltage on it. Is it possible that the L and N terminals are reversed (or there's reverse polarity on the incoming circuit) and that is causing some type of a fault within the controller?? That's the only way I could see connecting the cord with no power on it would have an effect on the controller.

Researching the internet and on other forums, there is a lot of chatter about these controllers failing with the reason given the refrigerator compressor will run on DC but not on AC.

The Danfoss controller 101N0500 as been updated several times. I was able to source the newer Danfoss Secop 101N0510 controller; however Danfoss Secop website now lists the 101N0510 controller as obsolete. The replacement is the Danfoss Secop 101N0511 controller but I could not find it available in the U.S. I did see that the Danfoss Secop 101N0511 controller was available in Europe.

In my case, I left the refrigerator to run on both AC and DC while the boat was stored on my lift for months. There have been several power outages over those months. It my best guess that during one those times the power was out, one of the circuits in the controller went bad and now the controller will not send current to the compressor if it is being fed AC. All of this is a wild guess on my part, but take into consideration that the controllers on my boat have a manufacture date of 2010. I am in Tampa Bay - the extreme high heat, extreme high humidity and salt air together plays havoc on all the electronics on a boat here.

I ordered new controllers for both refrigerators and will provide an update once I install them.

 

[km1125]

Researching the internet and on other forums, there is a lot of chatter about these controllers failing with the reason given the refrigerator compressor will run on DC but not on AC. ...

Yea, I'm seeing a lot of that. Couple folks ID'd some components (MOSFETs) to replace but not sure that's for the same failure mode.

Wouldn't doubt a surge/spike in the incoming AC lines took out both units at the same time.

But specifically I'm wondering/curious about that "plugging a cord in that has no power" that stops the unit from running on DC. That just makes no sense to me. If it were me, I'd plug in the cord but disconnect either the L or N wire at the controller to see which one actually makes a difference. Won't do anything to further troubleshooting if the controller is actually bad, but would help to understand what's actually going on.

 

[argus1]

I may have misspoke about the "plug having no power." I will check again when I get back on the boat later this week and post an update.

 

[argus1]

I finally got both refrigerators working. After installing new Danfoss Secop 101N0510 controllers, they both started woking immediately. Installing the controllers was pretty simple. Before installing the new controllers, they both would run on battery power but the 120v AC had to be off. Now they both work as intended. It appears that these controllers are sensitive to power surges.

 

[Chris-380]

I finally got both refrigerators working. After installing new Danfoss Secop 101N0510 controllers, they both started woking immediately. Installing the controllers was pretty simple. Before installing the new controllers, they both would run on battery power but the 120v AC had to be off. Now they both work as intended. It appears that these controllers are sensitive to power surges.

That’s awesome, glad you got them fixed. Thanks for the follow up!

I wonder if @speakrdude could fix those?

 

[argus1]

That’s awesome, glad you got them fixed. Thanks for the follow up!

I wonder if @speakrdude could fix those?

In my research, I found that a company in Poland is offering repair of the Danfoss Modules
Repair, Service Danfoss Compressor fridge Speed Controller Module 12v/24v - P.U.H. HESTA

There is a boat owner on another forum who posted a detailed analysis of the failure of the Danfoss 01N0500 Modules, citing multiple bad capacitors on the circuit board due to "age." wingless' Danfoss BD50F / 101N0500 Refrigerator Problems - Cruisers & Sailing Forums (cruisersforum.com)

The hardest part of the job was figuring out how to remove the Danfoss module. Any reference that I found on the internet said to remove the retaining screw first. There is no longer a retaining screw. The module just snaps in and out of place. It is held in place by a plastic tab on the back of the refrigerator. I had to remove the cooling fins screws and swing cooling fins out of the way to get enough room to remove the Danfoss module. I used a small flat head screwdriver to gently pry the module off. Then it was simple to pull wires off one at time on the old module and put the wire in the same labeled place on the new module.

 

[Creekwood]

In my research, I found that a company in Poland is offering repair of the Danfoss Modules
Repair, Service Danfoss Compressor fridge Speed Controller Module 12v/24v - P.U.H. HESTA

There is a boat owner on another forum who posted a detailed analysis of the failure of the Danfoss 01N0500 Modules, citing multiple bad capacitors on the circuit board due to "age." wingless' Danfoss BD50F / 101N0500 Refrigerator Problems - Cruisers & Sailing Forums (cruisersforum.com)

The hardest part of the job was figuring out how to remove the Danfoss module. Any reference that I found on the internet said to remove the retaining screw first. There is no longer a retaining screw. The module just snaps in and out of place. It is held in place by a plastic tab on the back of the refrigerator. I had to remove the cooling fins screws and swing cooling fins out of the way to get enough room to remove the Danfoss module. I used a small flat head screwdriver to gently pry the module off. Then it was simple to pull wires off one at time on the old module and put the wire in the same labeled place on the new module.

Well, if Wingless posted it, it must be correct! LOL