Pleasure Boat Refrigeration Technical Services from Hell

[Richard Kollmann]

I began my mechanical training in 1949. I took classes in aviation maintenance and engineering. Back then general experience in a wide range of technical subjects was sufficient enough to practice a mechanic’s trade. In those days there was an overlap in experience skills between Mechanics, Technicians and Engineers. Training and gaining experience then was less complicated as equipment hardware used common components and software controlled electronics was not involved in daily maintenance or engineering. One of the biggest challenges affecting mechanics, technicians and servicing personal today is a change in defining what is Repairable or Expendable. It was not too long ago that kitchen appliances, radios and lawnmowers were repairable. Do manufacturers plan for refrigeration design obsolescence in order to continue their replacement market or is it just an accident that their products are obsolescent because they are not maintainable and therefore must be considered expendable. When an automobile dealer mechanic can not correct a car’s problem he links the car’s computer to the manufacturers engineering department computer by way of the internet or asks the manufacturer for help. I find there are no means of contacting specialists in repair techniques on pleasure boat refrigeration. When you deal with as many pleasure boat refrigeration problems as I do, you will realize the job shops that build 12/24 volt refrigeration units are not interested in after market support. Here is how I define what should be an acceptable after market support strategy programs for all pleasure boat refrigeration manufacturers and US distributors if units are imported:

• Must have an available experienced Technician to answer technical questions with reasonable accuracy about the products you sell.
• These companies that design or market their products know something about the system’s weak points that could help owners/operators keep their refrigerators running longer. Why not post on the web, Service Bulletins or Technical Tips?
• Reliability engineering analyses is a simple tool developed from questions and technical data received from customers. Taking corrective action based on reported problems is a necessary strategy if a company wants to stay in business.
• Probably the poorest strategy for a distributor or sales person to deal with on a non standard refrigeration unit is to advise a boater to call a local refrigeration mechanic when they know this may damage the unit further.
• Probably the most discouraging advice a boater can receive is its, time to replace your complete system, because no one is interested in helping you with advice needed to repair the present system.

We have seen several pleasure boat refrigeration industries slowly disappear or be forced to diversify into other products because of what appears to be unproductive system design flaws and poor aftermarket strategies. SeaFrost may be the only older boat refrigeration company staying true to their product line with responsibility for After Market support over the years.

Many times normally maintainable boat refrigeration is bastardized to a point that when cruising it is not possible to make repair without the person that design it. When out of range of conventional aftermarket odd replacement parts, accessories or without enhanced repair knowledge boaters have to do without their refrigerator. Basic Danfoss air cooled refrigeration hardware is more apt to be available in most areas of the world. Add on gadgets that do little to enhance performance like electronic thermostats, water cooling condensers, keel coolers or other electronics will all put operating refrigerator’s reliability at risk.

Boaters today must wonder why 30 year old 12 volt Danfoss BD compressors perform well in systems made by the original Adler Barbour company, Electric Iceman company and a few others. The newer Danfoss BD 12/24 volt air fan cooled compressor systems will only last another 30 years if unproductive gadgets are omitted. Frigoboat BD water cooled compressor systems are replaced early because of refrigerant troubles. E Z Kold systems are replaced because of seawater interring the compressor’s refrigerant. Many Danfoss BD compressors are replaced even systems because a Service Technician or someone calling himself a Refrigeration Engineer advises that BD compressor rotor is locked up. Other BD compressor failures reported by Technicians From Hell were replaced because someone tampered with refrigerant or added too much refrigerant. Lack of experience, knowledge and incorrect advice from the system manufacturer’s representatives, along with absence of correct manual information and lack of helpful service bulletins are why experienced local mechanics are no longer interested in servicing small 12 volt refrigeration. Locked compressor rotors are common on large hermetically sealed compressors and even water cooled BD compressors but are extremely rare or never occur on air cooled BD Danfoss compressor units.

I received three emails in one month of service personal in Michigan advising boat owners that their Danfoss BD compressor needed to be replaced, my response is always the same. If this is an air-cooled unit, I inform them that there is an electrical problem with their system and warn them not to allow anyone to touch the refrigerant or touch its service ports. Usually this advice is always too late. Identifying trouble area must be accomplished first by Non Destructive testing before tampering with refrigerant. I can not tell you how many times mechanics will say a Danfoss BD compressor will not run if low on refrigerant, This is FALSE,. BD compressors will run even with no refrigerant in them. But if there is too much or contaminated refrigerant the electronic control module will detect high amperage and prevent compressor from running.

A few months ago I received an email that one of these mechanics from hell replaced a complete Danfoss BD electronically controlled compressor system because the compressor would not run. When the new unit would not run either, boat owner was told to contact me for help.
Replacing a system without following non destructive adequate testing first to verify the actual cause of problem is a mistake. Replacing a compressor or a complete system is as destructive as any test I know of. After boat owner spent $1000 or more I advised him that problem was and is still in the boats electrical system bad circuit breaker, old wiring, or bad wire connection.

Operators of 12/24 volt refrigeration units powered by a Danfoss BD compressor must understand that there are almost no technicians that understand modern hermetically sealed electronic compressor protective microprocessor control systems. The correct approach to finding and solving problems on one of these delicate units must be with simple non destructive tests. Anyone attempting to troubleshoot a Danfoss compressor system equipped with trouble LED codes must be aware that it will be necessary to interrupt code flashes yourself as manufactures manuals may be not be correct. Example, Locked Compressor Rotor or System over load, a code of 3 LED flashes I have never found it to be a Locked Rotor on an air cooled Danfoss BD compressor. In my library of Emails and forum posts I found 61 times where Danfoss BD compressor or system replacements advice was not supported by quantified facts. Three flashes of troubleshooting LED indicates a high amperage spike and very unlikely caused by a locked rotor.

For many years’ small refrigeration units manufacturers did not provide servicing ports to add or remove refrigerant. Adler Barbour and most home refrigerator manufacturers knew of the problems if their units could have refrigerant charge tampered with so their
units were designed without servicing ports. After the 1996 Clean Air Act all systems containing refrigerant must have a servicing port in order to remove and recycle refrigerant gasses.

[atoll]

hi Richard

perhaps you could advise I have a small air cooled bd/danfoss fridge,which ran great.

the other day I found the fan running with the units thermostat in the off position,and when switched on it failed to run.

this is an older unit with the micro processer,but no led indicator lights made by waeko.

ideas appreciated,possibly lightning strike?

[onestepcsy37]

Thank you, Mr. Kollmann, for all the help and advice you have provided to me and innumerable others.

[zboss]

I agree - you really go out of your way to help the cruising community and we are very grateful!

[JPA Cate]

^^^nicely said zboss,

Thank you for a most informative post, Richard Kollman.

Ann

[svfinlandia]

And another thank you! Very good information to know.

[a64pilot]

Richard,
I need help if possible, I too am an old A&P/IA, but started a little later than 49.
Anyway attached is a picture of what I have, I believe I have two problems, low refrigerant as I'm only getting frost on about 1/3 of my evaporator and possibly a bad thermostat as the unit will cycle off prior to what should be the set point.
Unit is sealed, I assume maybe R-12? I have done nothing so far except to clean electrical contacts and verify voltage at the compressor.

[ColdEH]

This thread should be made sticky , would help so many people.

Thanks Richard

Regards

[Richard Kollmann]

Originally Posted by atoll

hi Richard

perhaps you could advise I have a small air cooled bd/danfoss fridge,which ran great.

the other day I found the fan running with the units thermostat in the off position,and when switched on it failed to run.

this is an older unit with the micro processer,but no led indicator lights made by waeko.

ideas appreciated,possibly lightning strike?

Atoll, Without knowing what system you have it would only be just a guess for me to give good advice. There are a number of different ways your unit could be wired electrically, what compressor BD model do you have and who manufactured the system?

One test would be to disconnect fan black ground wire from module to see if compressor will then run.
And connect the two thermostat wires to gather again to see if compressor is running.
The Danfoss control module tells fan and or compressor when to run. Because some BD compressors are so quite when running best way to confirm it is running is if get warm in 20 minutes its running.

If compressor is not running there is an electrical problem unless someone has recently added refrigerant.
If compressor runs and there is little or no cooling there is a refrigerant problem, lack of or refrigeration flow restriction.

[Richard Kollmann]

Originally Posted by a64pilot

Richard,
I need help if possible, I too am an old A&P/IA, but started a little later than 49.
Anyway attached is a picture of what I have, I believe I have two problems, low refrigerant as I'm only getting frost on about 1/3 of my evaporator and possibly a bad thermostat as the unit will cycle off prior to what should be the set point.
Unit is sealed, I assume maybe R-12? I have done nothing so far except to clean electrical contacts and verify voltage at the compressor.

Your picture is of an older Adler Barbour Super Cold Machine with an off brand larger than normal non electronic compressor with motor brushes. These compressors did use Freon R12 and date back to the 1980s. Because this one has a stainless base plate and plastic fan shroud it may have been manufactured in early 1990s. This compressor worked fine until motor brushes failed to contact armature. Life of brushes in cool climates would last two to three times longer than in tropical climates so if compressor still runs I would keep it.

Evaporator should have at least 85% of its surface area covered with frost less that that would indicate loss of 2 to 4 ounces of R12 refrigerant needs to be added.

On your unit the thermostat starts and stops compressor based on evaporator temperature not box temperature. Contact area of the thermostat’s temperature sense tube with evaporator is important. Adler Barbour designs call for the last 5 inches of thermostat’s sense tube bent to a two inch U shape and to be clamped to evaporator under plate provided. If for some reason thermostat short cycles as you describe it is generally caused by sense tube touching cold evaporator or refrigerant line somewhere where it should not. To eliminate thermostat as a short cycling cause connect thermostat’s two wires together with power OFF as this is a true 12 volt compressor, unlike a low voltage AC Danfoss BD compressor, preventing dangerous sparks.

[SV THIRD DAY]

If I had a dollar for every time an owner of one of our CoolBlue systems called us after a local tech told him his compressor was dead only to walk him through some simple trouble shooting that ultimately revealed and easy (and cheap) fix maybe I could retire early.

Richard is right that getting good technical refrigeration service is almost next to impossible these days. The throw away culture sends way too many easily repairable systems to the scrap heap because it is easier for the poorly trained tech to slap in a new unit (and make a nice sales commission by the way) than learn what they are actually doing.

We have the advantage of having been doing this since 1968 and as far as I know we are the only marine refrigeration company with 7 day a week during any waking hour technical support line. Not some press 1 for English system to take you to someone in India, but every phone call is answered by the company owner who actually does the building of the systems. Even after 47yrs in the industry Randy Simpkins (the founder of technautics with a PhD in thermodynamics) still shakes his head almost weekly at some of the flat out horrendous tech support and advice being given to people. We actually had a call last week from a "refrigeration tech" that didn't know how to charge one of our units through the low pressure port...Randy and I both had to talk him through the process separately all the while he was charging the poor client $150/hr.....yikes.

As to keeping things simple....well some of that is sucoming to the marketing pressure to add special gizmos and features that clients are always asking for. It takes more time and educational work to explain why they don't really need what they want...because the client isn't always right. Just last week at the SSCA GAM in Annapolis we had a client that wanted us to put together a system for him that he could run and monitor and control through a smart phone app. I'm not exaggerating. He looked at us like we were from Marz as we explained to him just how important simplicity of design is for cruising gear. He ended up getting it in the end and bought a unit, but we had to deprogram lots of myths, cruise rumors, and 1/2 truths about marine refrigeration (including the "it has to be water cooled" myth).

As a live aboard cruiser myself one of the keys to our success has been the lost art of customer service. Almost everyone chants the customer service mantra...but form what I see of the industry its all talk with little actual follow through. Its also why we want to sell direct to the clients vs through a dealer network. I can't guarantee the customer service and tech support credentials of a dealer...but I can always answer the phone myself on a Saturday evening at 9:30PM. When someone has a refrigeration problem/question on the weekend Monday morning it just too long to wait. Plus...it gives me a good excuse to take a break from my never ending job of teak varnishing on this teak barge I was suckered into buying.....ha ha ha.

Cheers to Richard for all the great technical info he is willing to share and his straight talk on promoting the KISS principal for Marine Refrigeration.

[a64pilot]

Richard, I assume you mean short out the thermostat wire, maybe by disconnecting at the compressor end and running a jumper wire across the two terminals at the compressor end?
How can I service this thing? I have a HVAC license and about 2 lbs of R-12 in a couple of the small cans still left over from years past, but no R-12 hose set, but think I can borrow one.
There is one port, a tube that comes off of the compressor, is this the low side?

[a64pilot]

I'll first look to see it the temp sense tube is in contact with the evaporator, I can see easily how that could happen

[dohenyboy]

What Richard says is really true. Many technicians work by rote and not analytically.
Last year after a hiatus of not using the air conditioning, it would not come on. A local technician in the Bahamas came by. Its a Mermaid air conditioner with relays for the water pumps, since the pumps are shared between units. As I sketched out a rough schematic fear started to well up in his eyes. He promised to come back the next day and never came.
So I had to stop work and fix it myself. Reason was corroded out water pump and bad thermostats.
Richard, you could put together a book and nowadays very easily self publish. Every cruiser would buy a copy, like Calder's book on boat systems.
You should seriously think about it.


Sent from an undisclosed location on the high seas or from the lounge chair by the pool, you decide.

[wsmurdoch]

Originally Posted by dohenyboy

Richard, you could put together a book and nowadays very easily self publish. Every cruiser would buy a copy, like Calder's book on boat systems.
You should seriously think about it.

He has written books

Kollmann Marine

and

Kollmann Marine

Neither are thermodynamic texts. Both are the sort of practical advice a journeyman mechanic would pass on to his apprentice. I own them both. Along with his web site, they are priceless.

I have a 34 year old Kollmann Marine engine drive refrigeration system with a 125v backup condensing unit on my 34' Pacific Seacraft. It is built of all standard parts. Every piece of it can be bought off the shelf at any car parts store or refrigeration parts supplier. It works, and for ten years I have maintained it myself with occasional email advice from Richard.

I have had cold beer, frozen food, and ice every day in the Bahamas winter and spring for each of the last seven years.

www.kollmann-marine.com/Refrigeration/index.php?topic=401.0

and Irish Eyes to the Bahamas