Author Topic: Boat Refrigeration Technical Services from Hell  (Read 2554 times)

Richard

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Boat Refrigeration Technical Services from Hell
« on: October 04, 2014, 11:00:35 am »
 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 an aftermarket support strategy program for all pleasure boat refrigeration manufacturers and US distributors if unit is imported:
1.   Must have an available experienced Technician to answer technical questions with reasonable accuracy about the products you sell.
2.   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?
3.   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.
4.   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.
5.   Probably the most discouraging advice a boater can receive is its, time to replace your complete system, because no one is interested in helping 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 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 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 this 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 now 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, a 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 controls. The correct approach to finding and solving  problems on one of these delicate units must be with 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…

 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.
Prior to 1996 service ports were rarely installed on small completely sealed refrigeration systems like those using Danfoss BD and Swing compressors. Not only were leaks eliminated by not having service ports it also eliminated anyone from tampering with refrigerant.

In my first twenty years of writing five DIY books on boat refrigeration I could keep up with current changes in pleasure boat refrigeration. In the mid 1990s pleasure boat 12 volt refrigeration became popular do to advances in batteries and charging sources like wind, solar, water and high output alternators with smart voltage regulator. At the same time small 12 volt refrigeration became corrupted or debased by adding new elements such as water cooling and unnecessary electronic. Today it is not possible to cover each job shop assembled designs in a single book and company produced manuals do not describe particular problems with there designs.

When I realized I could no longer keep up with all boat refrigeration changes I opened in the year 2000 a web site to supply a method of revision services for each of my books. My boat revision Q and A forum through a word search can help guide anyone to thousands of boat refrigeration problems and solutions.

I still live up to my promise I made 30 years ago if you need an answer to a boat refrigeration question not fond in my book mail it to me or better yet post it on my Boat Refrigeration Forum.