We had been out on the water and had time to really work with our new modem for the high frequency (HF) (AKA "Ham" or "Single Side Band -SSB") radio. After we were done we noticed a hot electrical smell in the lower areas of the boat. Needless to say anything that smells like burning electrical insulation in a diesel filled floating flammable fiberglass box deserves immediate attention.
Clarice and I are generally VERY compatible (the classic "joined at the hip" type of couple). The big exception is when it comes to sleeping temperature preferences. I like it hot and Clarice likes it cold. Our marriage has only lasted 40 + years thanks to dual control electric blankets. On Salish Aire we have found that a dual control heated mattress pad works wonders at keeping the peace.
|Marriage saver (with outstanding warranty service)|
Back to the burning electrical device smell: It turned out the smell was pretty hard to track and clearly wasn't increasing so we gave up and finished out the day. It was when we went to bed that we discovered the source of the smell - my electric mattress pad control was the culprit. After doing an autopsy and discovering a burned out resistor on the circuit board we switched out my control for Clarice's never used one and slept the night away.
|Little resistor burning made a huge odor!|
After considerable pondering about the failure of the bed control I wondered if it had been overwhelmed by radio frequency energy from the HF radio (this may sound far fetched but these radios make lights flash and all sorts of things happen with electronics when they transmit). I emailed a published radio guru who replied that he just could not believe that was the source of the problem.
A week or so later I was doing some testing of our batteries and inverters (which turn 12 volt direct current (DC) power into 120 volt alternating current (AC) power so we can run common household appliances while we are underway or at anchor). Once again we smelled the acrid smell of burning electrical gear only this time we knew exactly where to look - yep the same resistor in the replacement control had burned out. Since the radio hadn't been on I was quickly able to put the pieces together and realized that our older inverter was very likely the cause of the failures.
A bit of inverterology is in order here. Turning AC power into DC power is really very easy and has been done for a lot of years. Turning DC power into AC power on the over hand is not so easy. In the past it was done by having AC motors turn DC generators which was a very cumbersome process. It was only with the advent of high speed solid state electronics that DC to AC inverters became practical. For those not familiar with AC power - the "A" (alternating) part involves the changing of the direction of the current 60 times a second (in the USA - other places only do it 50 times a second). This changing direction is a very natural outcome of electricity produced in a revolving generator which changes the voltage in pattern that when graphed creates a very nice undulating sine wave.
The earliest inverters just gave up on trying to create a lovely sine wave and instead created a chunky square wave pattern. Many AC electrical tools were happy with this but many electronic devices were not.
The next generation of inverters couldn't get to a true sine wave but did manage a compromise known as a modified sine wave.
It wasn't until recently that true sine wave inverters hit the market and solved the problem with unhappy AC electronic devices.
Salish Aire came to us with 2 inverters on board - the older one producing modified sine wave AC and the newer one pure sine wave AC. Both were very high quality devices made a few miles from our marina in Everett, Washington. The older inverter happened to be nearest to the larger of our two battery banks and so if I wanted to pull from that bank alone then I needed to pull AC from the boat from the older inverter only.
One last note of background information for those without a background in AC electricity. It is VERY difficult to put more than one electricity creating device on a single circuit at one time as the sine waves MUST align perfectly (be "in phase"). Back when my dad was working as an industrial electrician he recounts the story of bringing a second generator on line at the old ASARCO copper smelter in Tacoma (now just a superfund memory) and how, despite their best efforts to get the two sine waves aligned the generators made a huge thunk to get their magnetism aligned since the waves were not quite perfectly together (I've heard other stories of generators jumping off of their mountings due to this phenomenon). This becomes relevant later in our story.
It was during times that we were using the older inverter that the bed controls burned out so now we have moved to the true beginning of the story. My current assessment is that the blanket controls (which are electronic) don't like modified sine waves and so they quit working (our marriage likely will survive this insult as the manufacturer has told us they will honor their very strong warranty and we are expecting a new heated mattress pad any day now).
Clarice asked why we didn't just replace the older inverter with a newer one and I explained that I believed that the costs would be quite prohibitive and besides we had a working system - why fix what ain't broken! Looking into the costs a bit more I realized that the previous owner had installed very good equipment and that the system was expandable. I also learned that the newer inverter was designed so that it could be stacked with a second like inverter on the same power line and that they would automatically match sine waves. Before long we had talked ourselves into getting a new inverter that matched the newer of our original ones.
Here is where boat projects quickly get out of hand. The original older inverter was quite large and had been mounted right next to the engine room door so that I was constantly hitting it with my shoulder. It also stuck out about a foot into the space I need to access when I work on equipment behind the hot water tank. This meant that I had to enter the space with my arms over my head like a swan dive and then exit the same way in order for my shoulders to fit. We realized that in swapping out the inverter I could finally mount it next to the hot water tank and make equipment access much better. BUT in order to put it where I wanted to I would need to move the water pump for the pilot house air conditioner / heat pump. One project that was still in process was changing out the hoses on the 3 air conditioner / heat pump units as I had never done this last one (something about hoses that ran about 25 feet through small access spaces and ceilings seemed to make procrastination seem like a good idea). So, since the water pump needed to move anyway we added a 50 ft roll of expensive marine water hose to the pile and moved forward.
The remodeling project also involved moving several other electrical devices to make room for the new inverter. Finally the space looked ready and a friend helped me drop the 60 lb hunk into place - after I quickly unbolted some battery wires and other stuff to get them out of the access path.
Once the inverter was in its new location we worked together to run the new control wire under some drawers and through a wall and around a corner until it finally arrived at the hub where the system controls came together. I re-ran some short lengths of 120 V wire since the original wires didn't have the length to get to the new location (luckily the battery cables were long enough).
Finally the whole system was hooked up per the instructions and my drawings and the programming was done and only one inverter worked as the other one gave me an error message.
The next morning I worked to run new hose for the pump moving project (which turned out to be serendipitous as I found a couple of places the hose had started to leak). The hose ran through the ceiling, up through a "mouse hole" and behind the dash board, and under a floor panel to the air conditioner (which is back in a very small cupboard) and back down the way it had come but then in the engine room it took a turn over the hot water heater and out to a fitting on the outer hull - which required that I lay on my back on top of the water heater and force my arms through a maze of hoses to get the old one off and the new one on while trying to keep the $^&%(^&% fitting in sight using the *&^ headlamp that kept slipping off my sweaty forehead and making sure that the &*^(*&Y clamp wouldn't come loose and sink the boat.
|Air conditioner / heat pump located in a small cupboard (needless to say, the hoses connect to the BACK of the unit).|
|I had to lie on my back on the water heater (foreground) and reach past the hoses in the photo to remove then replace the hose where water exits the boat. NO FUN!!!|
|An example of one of the many "mouse holes" on the boat where wires, hoses, etc move from one compartment to another.|
Later in the morning I had my first call of several with Outback tech support - who were really very helpful but we just couldn't seem to find the gremlin in the system. I could make the old inverter the master and the new inverter the slave but for various reasons having to do with battery locations and the layout of the boat I wanted the new inverter to be the master and the old one the slave. I was beginning to think that it had a social issue and simply would not accept its place in the world. After several calls and a lot of over the phone troubleshooting the recommendation was made that I bring the old inverter into the factory (again, luckily its very close) for a firmware reburn.
Yesterday I got around to climbing into the lazarette and lying on my side to get the 60 lb beast unwired and removed from its home since 2009. I took it to the factory where they poked and prodded it for a day and then reported that it was flawless - they had failed to find the gremlin. In talking with the tech who met me at the door he threw out the idea that maybe the Cat 5 computer cable that connects the inverter to the hub was flawed. This seemed very remote to me as the inverter was happy to communicate with its programming "Mate" as long as I didn't tell it to be a "slave".
|Old inverter in the lazarette. I have to lie on my side to access this one.|
Once back on the boat I climbed into the lazarette and manhandled 60 lbs up onto the bulkhead wall and rewired everything and it failed again. In the end the cable was the issue (all I can guess is that one of the eight wires had a bad connection but it was not needed when only one inverter was on line so it was never revealed until now as a problem). Needless to say the new one had to be run from the lazarette through a tiny hole into the engine room and then up through a mouse hole into another little space then through another mouse hole and over a ceiling panel and through another mouse hole before it reached the hub but once it was there IT WORKED!!