How hot is too hot for Frigoboat's Merlin II?

[Sailor647]

Originally Posted by senormechanico

Salt with any moisture is a conductor and thus the whole board is racked with bogus resistors every which way. No wonder it doesn't work !

Would fresh water have the same effect?

[senormechanico]

It depends on the particular circuit, but it's nowhere near as conductive as salt water.
If you wash a board as I previously described, dried it thoroughly, the chances of it working are pretty high as long as the salt and resultant (temporary) shorting it caused didn't burn out any components.

Dampness from high humidity is rarely enough to cause problems unless the components are in a very cool place which then gets a blast of warm damp air.

I used to sell and repair TV sets back in the '70's and '80's.
Often, people wanted me to deliver a new, in the box TV console to their warm house for Christmas. The set had been kept in an unheated warehouse in freezing, snowy weather in the PNW.
I always tried to tell them the set needed to be acclimated to the temperature of the room for a few hours before being turned on or the cold components would condense moisture from the room.

One family couldn't wait and immediately turned on their top of the line Zenith console as soon as it was unboxed. The picture tube second anode voltage of 35KV was too much for the condensation all over the rear of the tube and it arced several times with a lot of noise. The microprocessor in the remote control locked up with the volume at maximum. Did I mention this had four speakers and a high performance audio system?
It was stuck on channel 2 and could NOT be turned off. I pulled the plug.
They were convinced it was a lemon and insisted I bring another or return the purchase price including delivery. I finally got them to relent and wait a couple of hours and I'd return which I did.
With much anxiety and ears plugged, they sat there as I turned it on, adjusted the volume and changed channels.






It worked perfectly.

[Richard Kollmann]

Re: How hot is too hot for Frigoboat Keel cooler water cooler systems in extended warm ambient conditions should be an important warning.

[senormechanico]

I stuck a 140f. snap disc on the top of my BD35 connected to a good sized fan exhausting to keep it happy. It never runs unless the freezer is refreezing a 5 lb Arctic Ice block and the water temp is in the mid 70s and cabin is in the high 80's or above.

[a64pilot]

Google "conformal coating" and buy some and coat the new boards, it is what is usually done for boards used in high humidity environments, often it is what makes "marine" electronics, marine.
I'd be surprised if they aren't coated already, does it look like they have a layer of clear paint covering the entire board?

Here, read this

https://en.m.wikipedia.org/wiki/Conformal_coating

Sent from my iPad Pro using Cruisers Sailing Forum

[SV THIRD DAY]

Without air movement on the Electronic controller it's a burnout waiting to happen in tropical climates and it's why Danfoss requires electronic controller fan/air cooling on the controller in the tropics. So get an auxiliary fan and get some air movement on those electronics. The No 1 and No 2 failure points for the electronic controllers are Heat and Water damage. It's a relative easy fix the heat issue, just add a cooling fan. Then onto the water splash problem...

[Sailor647]

Originally Posted by Richard Kollmann

Re: How hot is too hot for Frigoboat Keel cooler water cooler systems in extended warm ambient conditions should be an important warning.

No, it is not a warning. Because, I did NOT ask how hot is too hot for a "Frigoboat Keel cooler water cooler systems".

I DID ask how hot was too hot for the Merlin II circuit board - because, I do not know. I am not an electrical engineer. Or an electronics engineer, or even an electrician. I don't profess to know everything about all parts of each and every system on our boat.

Which is why I'm so grateful for the help here on Cruiser's Forum. Seriously.
Thank you.

[Sailor647]

Originally Posted by SV THIRD DAY

Without air movement on the Electronic controller it's a burnout waiting to happen in tropical climates and it's why Danfoss requires electronic controller fan/air cooling on the controller in the tropics. So get an auxiliary fan and get some air movement on those electronics. The No 1 and No 2 failure points for the electronic controllers are Heat and Water damage. It's a relative easy fix the heat issue, just add a cooling fan. Then onto the water splash problem...

Got it. Thanks for the help. Will be getting a fan installed shortly.

[Sailor647]

Originally Posted by senormechanico

I stuck a 140f. snap disc on the top of my BD35 connected to a good sized fan exhausting to keep it happy. It never runs unless the freezer is refreezing a 5 lb Arctic Ice block and the water temp is in the mid 70s and cabin is in the high 80's or above.

I'm not sure what this means. What is a 140f. snap disc? Connected to a good sized exhaust fan? How big is good sized?

Thanks!

[Richard Kollmann]

You do not need to be an engineer to know a compressor and its electronic module is running hot. If you can not keep the palm of your hand on dome top of compressor it indicates both compressor and module are running in an overloaded condition. If this overloaded condition remains for extended periods of time module and even major system failures will result.

Danfoss BD compressors were intended to have supplemental fan cooling. When there is a lack of heat removal at compressor and condenser keel cooler the liquid high refrigerant pressure increases and generates more heat. Compressor manufacturers provide application operating limitations on each model compressor they sell. Once a non technical operator believes a BD compressor may be running too hot he can check actual refrigerator amperage draw for his system against Danfoss specifications for unit speed and BD model.

Options available to reduce Frigoboat keel cooler model’s Danfoss BD compressor heat:
Reduce compressor operating speed.
Add Frigoboats second air cooled condenser designer to remove heat in series with present keel cooler.
Supplement cooling compressor with a 50 CFM fan.
Make sure location of compressor area space is well vented.

[senormechanico]

Originally Posted by Sailor647

I'm not sure what this means. What is a 140f. snap disc? Connected to a good sized exhaust fan? How big is good sized?

Thanks!

Just one example:

White Rogers 3F01 140 Snap Disc | eBay

Exhaust fan varies, just make sure compressor is not breathing the same air being recurculated, but is getting air not exhausted.
For example, these fans are a favorite according to CF posters for their low noise and decent air delivery:

noctua fan | eBay

[Sailor647]

Originally Posted by Richard Kollmann

You do not need to be an engineer to know a compressor and its electronic module is running hot. If you can not keep the palm of your hand on dome top of compressor it indicates both compressor and module are running in an overloaded condition. If this overloaded condition remains for extended periods of time module and even major system failures will result.

Hi Richard,
Thank for your help. I went back and re-read my original post to make sure I hadn't written it wrong.

The compressors aren't running hot at all. We can keep the palms of our hands on them, no problem. So, they are not/have not/do not run in overload condition. Did I mis-state something somewhere?

We simply had a failed circuit board. It failed because it got wet. We thought about installing a box around it to protect it from moisture, but we wanted to make sure that enclosing it wouldn't create more problems for the circuit board in the way of heat. It's really not that complicated of an issue, now that I understand it a little better.

Both systems are running fine (compressors are not hot, fridge is cold, freezer is frozen) - even in this hot climate. We are very happy with the systems we have. They do an amazing job of keeping our food cold and frozen. And making four trays of cocktail ice daily.

Thanks again.

[ErikFinn]

Well, COASTAL CLIMATE CONTROL, INC. has sullied their reputation by denying their responsibility with your one year old 4000 USD "marine" system, for sure. What they should have done is just send you a new control unit no questions asked, in the name of good will and customer satisfaction and protecting their reputation as a reputable "marine" fridgeration equipment disributor. Instead their foul practise is now in internet on the leading boating forum for everyone to see. Such short sighted unprofessional conduct. Better stay away from COASTAL CLIMATE CONTROL, INC. folks. Doh.

If your compressor and control unit location does not have a good circulation of fresh air you should look for ways to remedy that. If the space is an inclosed space it's a killer especially for the electronics. Install fans or even a few. Try find a way to get fresh new air in and hot air out of that space, so that it's not just the same old hot air only moving in there. Mr Kollmann is THE Guru when it comes to marine refridgeration, have a look at his advice regarding fans:

Kollmann Marine

Furthermore, if you want a quiet and low power consumption fan get a Noctua, the brown color line fans. Look at their specs at their website and compare to any other fan. You might be able to find other fans with higher CFM or Static Pressure but they will be much noisier and draw much more amps. The Noctua Industrial line is more robust but overkill imho and they are noisier and draw more. PWM connector fans I understand require a motherboard for functioning but I'm not sure if they can be adopted; so I bought 3-pin fans instead. There are other threads here on CF about fans also. Cheers.

[Sailor647]

Originally Posted by senormechanico

As a retired electronic tech (now Bernina sewing machine tech) it's pretty obvious to me that it is indeed salt on that board.
Don't laugh, but you might be able to restore it to good working order with hot water and a toothbrush.
Dunk it in some hot water, let it soak for awhile, then give it a workout with a toothbrush. Not really hard, but just like you would be brushing your teeth.
Brush it for ten minutes, rinsing it often each time in new fresh water (doesn't have to be hot rinse).
Let it dry in the sun for a bit, and if you still see any whitish stuff, redo the above until it's nice and clean.
Dry it out thoroughly in the sun (twenty minutes in San Carlos ought to do it !), and try it. You might be amazed, but in the past, I repaired a lot of VCR's that had soda pop spilled in them with similar damage.
I removed the damaged boards and ran them through the dishwasher in my house.
Voila ! Just like new.

Senormechanico, I'd like to buy you a beer. Or two. Or three! Your fix WORKED!!! I soaked, then brushed and rinsed the salt-encrusted Merlin II for a full ten minutes (timed) as you recommended. Twenty minutes in the sun, then a cool down (for me and the board) inside the air conditioned boat before installing it.

Today is July 8, 2016 at 1:00 pm. It is 97F/36C outside in the shade (and rising). The water temperature one foot /.3 meters below the water surface (keel cooler position) next to our boat in Marina San Carlos is 90F/32C. Yes, bathwater warm - and seriously polluted. (But that's another story under lack of pump-out services, cultural differences, or ?? Please don't hijack this thread. lol)

The Merlin II that we just cleaned and reinstalled is running at speed three. No fault code. The compressor is warm, but not hot - I can easily keep my hand flat on top and not get closed to uncomfortable or burned. The inside temperature of the fridge unit (with the replaced Merlin) is 35F/2C degrees, manual thermometer set on speed 4 1/2.

Now, should the Merlin II stop working in a day or two, I will follow up with another post.

Thank you for your help. We really, really appreciate it!

PS - We still have no idea how salt water would have splashed into that area. It may involve emptying out the laz and observing while we are re-crossing the SOC in 30 knot winds, with 8-10' seas at 4-5 seconds like our most recent crossing. LOL Or better yet, I'll put the GoPro down there and see what happens.

[Sailor647]

Originally Posted by a64pilot

Google "conformal coating" and buy some and coat the new boards, it is what is usually done for boards used in high humidity environments, often it is what makes "marine" electronics, marine. I'd be surprised if they aren't coated already, does it look like they have a layer of clear paint covering the entire board?
Here, read this: https://en.m.wikipedia.org/wiki/Conformal_coating

Sent from my iPad Pro using Cruisers Sailing Forum

I sent the link to Info at Climate Control and asked if the Merlin II's had this coating. They replied, "Yes. Merlin II's are conformally coated."

They did indeed have a layer of what looks like a very thin sheet of plastic over the back side. After cleaning, the board is working again.

THANKS!