Refrigerators not Working

Wow - I am amazed with the knowledge here. I am going to try some simple things that I can know that I can handle. I did check all other electrical accessories, stove, microwave, etc. Everything but the refrigerators works. I do plan to replace the batteries this weekend. I will also check the GFCI in the head also. If I can't figure it out, then it is call to get MarineMax to look at it. I know that need to replace the batteries before I call MarineMax; three years ago they came out to check the alarms that I was getting and charged me $300, just to tell me the alarms were going off due to low voltage and the batteries need to be replaced.
 
Dani-Lu said:
You normally should get 3 years on wet batteries, and 5 years on AGM.
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Heat and humidity will kill a battery. My boat is stored at my dock in Tampa Bay in a salt air environment. We have temperatures above 85 degrees with very high humidity 7-8 months a year; in summer months the temperatures is 90 degrees or higher. Boat is sitting the sun all year; I don't think the engine hatch is the best environment for boat batteries.
 
Checked the boat this afternoon. Disconnected the batteries and checked each one with a multimeter, each read 12.8 - 12.9. I get 10.8V from the VesselView display on the dash. Not sure what to make of the difference, but it appears that the batteries are okay. The GFCI in the head does not control the refrigerator, it controls other outlets in the cabin but not the refrigerator. I noticed when the battery switch is turned off, the cabin refrigerator's interior light flickers and when I turn the battery switch back on the flickering stops. I pulled the cabin refrigerator out and disconnected it from the 110 outlet. The outlet has power, confirmed by plugging a dehumidifier into the same outlet. Used the multimeter to check DC power to the refrigerator and it read 13.1V. I then removed the AC cord from the refrigerator to check the fuse; fuse is good. I discovered the cabin refrigerator will run on DC if the 110 AC cord is disconnected from where it connects to the refrigerator. When I connected 110 AC cord back in the refrigerator stops running. It does not matter if shore power in connected or not or if the refrigerator circuit breaker is on or off. The refrigerator will run on battery only when if the 110 AC power cord is not connected to the back of the refrigerator. As soon as the 110 AC cord is connected the refrigerator stops running. Don't like giving up, but it now may be time for someone with more technical skills than me to look at it.
 
argus1 said:
Checked the boat this afternoon. Disconnected the batteries and checked each one with a multimeter, each read 12.8 - 12.9. I get 10.8V from the VesselView display on the dash. Not sure what to make of the difference, but it appears that the batteries are okay. The GFCI in the head does not control the refrigerator, it controls other outlets in the cabin but not the refrigerator. I noticed when the battery switch is turned off, the cabin refrigerator's interior light flickers and when I turn the battery switch back on the flickering stops. I pulled the cabin refrigerator out and disconnected it from the 110 outlet. The outlet has power, confirmed by plugging a dehumidifier into the same outlet. Used the multimeter to check DC power to the refrigerator and it read 13.1V. I then removed the AC cord from the refrigerator to check the fuse; fuse is good. I discovered the cabin refrigerator will run on DC if the 110 AC cord is disconnected from where it connects to the refrigerator. When I connected 110 AC cord back in the refrigerator stops running. It does not matter if shore power in connected or not or if the refrigerator circuit breaker is on or off. The refrigerator will run on battery only when if the 110 AC power cord is not connected to the back of the refrigerator. As soon as the 110 AC cord is connected the refrigerator stops running. Don't like giving up, but it now may be time for someone with more technical skills than me to look at it.
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that’s weird that it quits if the breaker is off.


My guess would of been it was the rectifier that takes the 120v AC that converts it to 12v dc was bad…. But it shouldn’t matter if it’s plugged in if power is shut off to the receptacle. if the 120v receptacle is dead, it should run on the 12v DC….

did you do anything with the cockpit fridge?
 
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Chris-380 said:
that’s weird that it quits if the breaker is off.


My guess would of been it was the rectifier that takes the 120v AC that converts it to 12v dc was bad…. But it shouldn’t matter if it’s plugged in if power is shut off to the receptacle. if the 120v receptacle is dead, it should run on the 12v DC….

did you do anything with the cockpit fridge!
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I didn't want pull out the cockpit refrigerator because it was it is lot harder to get back in. Not sure if I pull it out that I will be able to diagnose and fix anything. I was thinking of connecting the cabin refrigerator to an extension cord connected to a 110v outlet outside of the boat to see if will run then.
 
argus1 said:
I didn't want pull out the cockpit refrigerator because it was it is lot harder to get back in. Not sure if I pull it out that I will be able to diagnose and fix anything. I was thinking of connecting the cabin refrigerator to an extension cord connected to a 110v outlet outside of the boat to see if will run then.
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I assume it’s a duplex receptacle. Put a digital meter in the receptacle to check the voltage. The while that is lit up (with the voltage reading) have a hair dryer plugged in and turn it on and see what happens to the voltage. It seems like the AC voltage is enough to make the fridge think it has power and not allow it to switch over to DC, but not enough to run the fridge though, that is the only thing I can logically think of as to why when you unplug the AC it runs on DC….
 
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Did you ever state exactly which model(s) fridges we're talking about? In one earlier post you reference the CRX but didn't state a model. Do your fridges use the MPS35 rectifier module?

When you wrote "I then removed the AC cord from the refrigerator to check the fuse; fuse is good."... which fuse was that? There should be at least two... and AC and a DC fuse, but there could be a third.

If you are using the MPS35 modules, you could be able to check DC in and out of that module and whether there's DC out if there is the presence of AC in.
 
km1125 said:
Did you ever state exactly which model(s) fridges we're talking about? In one earlier post you reference the CRX but didn't state a model. Do your fridges use the MPS35 rectifier module?

When you wrote "I then removed the AC cord from the refrigerator to check the fuse; fuse is good."... which fuse was that? There should be at least two... and AC and a DC fuse, but there could be a third.

If you are using the MPS35 modules, you could be able to check DC in and out of that module and whether there's DC out if there is the presence of AC in.
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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.
 
argus1 said:
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.
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You can check the control boards with a little LED light. If bad, you can purchase the control units separately.

Google danfor secop BD35 controller and there will be some youtube video's on how to diagnose.

Basically a cheap LED placed between + (DC Positiive) and D will put out a series of flashes indicating the issue.


Capture2.PNG



Capture.PNG
 
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argus1 said:
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.
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There should be a spot to measure voltage on the secondary side of the rectifier to see what dc voltage it’s putting out
 
It’s not 110 or 120 volts. It should be close to 120v if there is a voltage drop and it’s 110 volts, that could make the difference also… did you get an exact reading, and if it changes with a load, like a hair dryer….

It is more likely the controller, but it’s odd both went out at the same time…

argus1 said:
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.
Click to expand...
 
Chris-380 said:
It’s not 110 or 120 volts. It should be close to 120v if there is a voltage drop and it’s 110 volts, that could make the difference also… did you get an exact reading, and if it changes with a load, like a hair dryer….

It is more likely the controller, but it’s odd both went out at the same time…
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It read with the multimeter 122.1V and when I ran a heat gun on the same outlet it dropped to 116V.
 
Chris-380 said:
It’s not 110 or 120 volts. It should be close to 120v if there is a voltage drop and it’s 110 volts, that could make the difference also… did you get an exact reading, and if it changes with a load, like a hair dryer….

It is more likely the controller, but it’s odd both went out at the same time…
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I seriously doubt that. If the AC power was directly powering a motor (like an induction motor), then I might be inclined to agree, but since in this case it's all rectified and regulated then I'd bet it would would work down to 85 or 90VAC.

Quite likely, it's sensing the AC input and flipping the relay but the rectifier/regulator from the AC is defective.
 
km1125 said:
I seriously doubt that. If the AC power was directly powering a motor (like an induction motor), then I might be inclined to agree, but since in this case it's all rectified and regulated then I'd bet it would would work down to 85 or 90VAC.

Quite likely, it's sensing the AC input and flipping the relay but the rectifier/regulator from the AC is defective.
Click to expand...
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
 
Chris-380 said:
There should be a spot to measure voltage on the secondary side of the rectifier to see what dc voltage it’s putting out
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I don't think you will find a rectifier (in the pure sense) in these controllers. The compressor motor is 3 phase and the controller is a frequency drive which the source voltage can be 12/24VDC or 120VAC in the model that @argus1 is trouble shooting.
The controller will trip off line in under voltage conditions. As both refer's are having problems I'd still be going through the power to them thoroughly.
Possibly first to remove all DC power to the units and see if they will start and operate on AC power. Then remove all AC power and see if they will operate on DC power. Again, if your AC circuit in the boat will not deliver the amperage to hold over 100 volts during compressor start the controller will shut down the refrigerator regardless if DC power is present or not.
I would measure the voltage at the AC power connections on the controller and turn on the refrigerator using the thermostat. Then note the drop in voltage .
 
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