Visit our Popular Forums

YoloSF · 18-10-2017, 17:05

Hello,

I have a BD35 with Danfoss control module and the fridge is not running. I’m getting a 2 light blinking error. I would think that if I simply disconnect the fan I should be able to by pass it and see it run without the fan asked on that, but it’s not the case. I’ve been moving around the wires and looking for corrosion, etc. And in doing so heard it and felt it running for a few seconds then it shut off again which leads me to believe there’s still a loose connection or corroded wire I haven’t narrowed it down to. Before I spend more hours tracking it down, could it be a faulty control module? Especially given that disconnecting the fan and shutting it off for a minute doesn’t get it running? It’s getting 12.8v measured at the control module and the freezer is running fine so it’s not a voltage issue. Any tips would be appreciated!

Thanks

**a64pilot** · 18-10-2017, 17:16

First thing, run a new heavy gauge wire directly to the battery bank.
If it then works then you definitely have a voltage problem.
From my understanding, that is the most likely fault.
You can take one battery to get close to the controller as opposed to having to run a long length of wire.
If you have a separate fridge compressor that is close to the freezer one, then of course you can unplug it and plug it into the freezer compressor for trouble shooting.

OzePete · 18-10-2017, 17:26

There was quite a lot of discussion regards this issue, here: http://www.cruisersforum.com/forums/...ol-184322.html

Including this:
OK so maybe it's a good time to provide a 'KISS' list of things to check if your DC compressor will not run: (This is a check list we send to our Ozefridge customers and others if needed.)

First disconnect any high voltage supply.

1:Check DC voltage-in on the compressors electronic unit, both with compressor off AND when it runs or tries to run.
A: If the voltage is low, or if the voltage is OK but drops away more than say half a volt at start up attempt, then check the power supply, terminals, wiring and batteries. (An amp meter reading when attempting to start would be useful. If the amps go way above normal then the compressor may be mechanically stuck.). If the voltage is OK and there is little dip upon a start attempt then go to step 2.

2: Bridge the lowest and third lowest terminals and power up. (These terminals C & T on Secop, Danfoss and most other compressors, are the thermostat switch)
A: If the compressor starts and runs normally, leave the bridge in place and run manually until you can replace the thermostat. (YOU become the thermostat!) If still not running go to step 3.

3: Remove both fan wires from electronic unit and attempt a start.
A: If this allows the compressor to run, replace fan. Note.. fan should not exceed 6 watts. If still not running go to step 4.

4: Remove electronic unit from the compressor revealing three terminal pins on the compressor. Use a multi-meter to check resistance between each combination of two pins (of the three) and from these pins to the compressor case (Ground)
A: The resistances should be uniform at approx 2.0 Ohms for BD50, 2.3 Ohms for BD35. Others may have different Ohms readings but OK if they are all similar. If there is no reading or a much higher reading between the pins or if there is leakage to the ground then the compressor is dead. If the readings are OK the compressor is most likely OK so go to step 5.

5. Replace the electronic unit.

I hope this helps..
Cheers, Ozepete from Ozefridge.com.au

Typhoon · 23-10-2017, 05:14

Also, another question is , has anyone tampered with the system ?

If not, then Pete's recommendations are a good starting point for figuring out whats going on , just a process of elimination.

Regards John.

Thumbs Up · 13-01-2018, 07:21

My fridge stopped cooling last night. What could it be? I just got back to the boat four days ago, started the fridge and it has been working fine. this morning, no frost, no cold. I understand that these systems are under greater pressure when they are off so I don't think the coolant leaked out. The compressor is running but only slightly warm to the touch (normally the compressor would be much warmer). The compressor sounds fine. It is an Isotherm unit with small freezer compartment inside (not that that matters). Has the danfoss bdf35. WHAT COULD THE PROBLEM BE? some sort of clog? I don't see a capillary tube. Should I bang on something? Flip it over? try to "burp" it? My beer is getting warm! Leftovers are going bad! I can troubleshoot the electrics but it is not that. Should I junk it! (Unit is 8 yeats old) Thanks in advance for any suggestions. Also does anyone know if the Morningstar 300 watt inverter can start a "dorm size" fridge? And finally has anyone tried one of the newer "inverter" refrigerators (SAMSUNG) on their boat. Pretty sure that my Morningstar will run one but am worried that circuit board on the Fridge won't hold up to the marine environment.

Diesel Bill · 13-01-2018, 08:07

Must be contagious. My original 1980 Norcold 6.5 C.F. died 2 months ago. The compressor was running constantly but not cooling. After removing from the built in area, I found the high side tubing going to the freezer had chafed on the back panel sheet metal and had lost the gas charge. The 2 fans were also not working. I priced a replacement at various venders and the lowest price was almost $1400.
I remember reading Sailor Chick's thread on installing an apt. style 120v fridge and thought why not. I found a similar sized fridge at Target and they matched the Lowes advertised price of $179.00 . It's a whirlpool brand and light enough that I was able to remove the doors and carry it through the cabin and down the steps to the galley.
The compressor draws 0.98 amp. Volts X amps = 120ish watts. I found on e-bay a low frequency true sine wave 3000 watt inverter with free delivery for $189.00.
So far the inverter runs the fridge very well. So for less than $400. I have a new fridge and a pretty nice inverter good for running other things also.
Thank you Sailor Chick for the idea.

Typhoon · 13-01-2018, 09:55

Quote:

Originally Posted by Thumbs Up

My fridge stopped cooling last night. What could it be? I just got back to the boat four days ago, started the fridge and it has been working fine. this morning, no frost, no cold. I understand that these systems are under greater pressure when they are off so I don't think the coolant leaked out. The compressor is running but only slightly warm to the touch (normally the compressor would be much warmer). The compressor sounds fine. It is an Isotherm unit with small freezer compartment inside (not that that matters). Has the danfoss bdf35. WHAT COULD THE PROBLEM BE? some sort of clog? I don't see a capillary tube. Should I bang on something? Flip it over? try to "burp" it? My beer is getting warm! Leftovers are going bad! I can troubleshoot the electrics but it is not that. Should I junk it! (Unit is 8 yeats old) Thanks in advance for any suggestions. Also does anyone know if the Morningstar 300 watt inverter can start a "dorm size" fridge? And finally has anyone tried one of the newer "inverter" refrigerators (SAMSUNG) on their boat. Pretty sure that my Morningstar will run one but am worried that circuit board on the Fridge won't hold up to the marine environment.

Hi thumbs up

Is this a fridge or a ice box conversion unit ?

Regards John

Thumbs Up · 13-01-2018, 10:12

I have a Morningstar 300 watt pure sine inverter that can handle an inrush current up to 600 watts. I bought it originally with plans to run one of the new inverter technology fridges which have variable speed compressors much like the danfoss 12/24 volt ones. A traditional fridge usually has a big inrush current but I am wondering if newer models require less amperage to start. The Samsung inverter frdges are available here but expensive. They say they have a ten year warranty but I think they have a tendency to blow out the circuit boards. (another idea would be to "marinize" the circuit board with some type of coating or encapsulation). I could measure the inrush on some fridges if I had a proper AC clampmeter with a peak hold function so am wondering if anyone else has gone down this path and what they found out. Of course I could get a larger inverter but am trying to keep this "low budget"

leftbrainstuff · 13-01-2018, 10:27

Replacement is putting the cart before the horse.

Diagnose the fault first. It could be as simple as the thermostat. (Experienced this twice) or a corroded connection and too much voltage drop. (Experienced this once)

Try this approach (you mentioned your compressor runs)
1) check electrics physically. Try wiggling connections.
2) check pipe runs for chafing (your comments hint at charge loss)
3) listen near the evaporator (in the fridge). Can you hear the liquid to gas station change. (Assuming you have a capillary). I've replaced a condenser due to a blocked capillary. Tricky to diagnose until it blocked completely)
4) check system pressures. Some experts advise against this but if you aren't experienced enough to detect the subtle 'burbling stream' noise then this is a proven and foolproof diagnostic approach. You must be very pedantic and not introduce moist air when connecting or disconnecting gauges. I purge with refrigerant.

Fix the problem. It ain't rocket science. The danfoss systems are simple enough and quite reliable.

OzePete · 13-01-2018, 14:51

Hi Thumbs Up. If your BD35 compressor runs then the problem is either loss of refrigerant (most likely) or a blockage. Suggest you check for leaks and repair same, remove the 'pencil' type dryer (they are rubbish!) and fit a proper 032 solid core type, evacuate and re-gas. I would also suggest you would be far better to repair your system than replace with a domestic fridge for the following reasons.
1: Domestic fridge construction is not suitable for marine application specially electronic components which are not conformal coated as they are with dedicated marine systems. Also the cabinet insulation is usually minimal and therefore less efficient.
2: Only DC marine system compressors are engineered to cope with movement and operate at angles. (Try moving a domestic fridge or lean your kitchen fridge over on a 30 degree angle while running and you can hear the motor-compressor banging against the interior walls of the compressor case... metal to metal!)
3: DC compressors are 3 phase, the most reliable type of motor and most are now soft start reducing in rush stress on electronics.

Cheers, OzePete Ozefridge | 12 Volt Refrigeration Systems

Bean Counter · 13-01-2018, 14:59

http://www.penguinfrigo.co.uk/assets...0Diagnosis.pdf

May be useful, there are other U tubes as well

https://www.youtube.com/watch?v=gvD2kkJsJPs

**a64pilot** · 13-01-2018, 15:44

Ref the inverter fridges.
It’s easy to find current one draws once you have it, just use a kill-a-watt meter. Of course you have to have it to measure it, unless a store would let you.

Then to “marinize” a circuit board, there is a product just for this, has been used for decades. It’s called conformal coating and is as easy as painting the board with clear varnish, except the conformal coating is designed specifically for protecting circuit boards.
Child’s play to do. I conformal coat boards all the time if I’m mounting something in a wet environment.

Thumbs Up · 13-01-2018, 17:21

Thanks for the replies.
Coldeh asked if it is a fridge or built in: it's a fridge
It is definitely not electrical, the compressor runs.
If it had lost the charge due to a leak I think it would have happened over the summer because the pressure is much greater when the system is not running, and it worked fine for a few days after I got back but last night stopped cooling.
So it seems like we are going with a blocked capillary and replace the dryer while I am at it?
I will comment on Ozepetes other suggestions:
The cabinet insulation on these small Isotherm fridges is minimal and probably no better than a domestic fridge
Operating at angles isn't an issue for me because it is a catamaran
The new fridges that they call "inverter" models actually use variable speed 3 phase compressors similar to the "dc" models, have low inrush current and are very efficient.
As for A64"s advice, I doubt that a "killowat" meter would accurately measure inrush current (The peak current required to start the compressor as opposed to the current required to keep it running), but that would be a good approach but I would need a good clamp meter with a peak hold function. As for the conformal coating, I like that idea but don't know if I can buy it here. They do sell Samsung inverter fridges here though with a 24"x24" footprint, separate freezer door, cold water dispenser, stainless steel doors, etc. They look very nice but cost way more than a standard unit. A morningstar 300 pure sine should be able to run one fine but I am not sure about the "defrost" function. Maybe it can be disabled.
As for my Isotherm. If a blocked capillary is a well known problem, and if a bdf35 is regarded as having a useful lifespan of way more than 8 years, then I guess it would be worth having a refrigeration guy over to fix it. Anybody know?