Tag Archives: AC to DC converter

2014/04/04 (F) Converted

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AALL*BRITE showed up this morning as scheduled to wash the coach and clean/polish/seal the Alcoa wheels.  The three man crew started on the roof and worked their way down and around.  They used a “spot-free rinse system” that did not require them to hand dry the coach.  When they were done with the wash and rinse they went to work on the wheels which were a messy job that involved a lot of hand work.  The coach looked good when they were finished.

I went down mid-morning to check on Jeff and Kathy’s motorhome.  Everything had worked through the night.  I went back later and disconnected John’s 20 A battery charger.  I then had Jeff disconnect the +12 VDC house battery cable.  With the converter 120 VAC power cord was still unplugged the voltage at the converter output terminals was zero, as it should be.  I plugged the 120 VAC cable back in and re-checked the voltage at the output terminals.  It measured 13.5 VDC so the converter was, in fact, producing an appropriate voltage with no load attached.  That did not prove that it was functioning properly as it could still be unable to maintain that voltage while supplying current to a load, but it was at least trying to do something.

The house battery bank had been disconnected for over 15 minutes.  The resting voltage was 12.7 VDC, so the batteries were fully charged.  My best guess was that Jeff and Kathy did not have a battery problem.  I unplugged the converter and reattached the DC negative cable.  We then reconnected the battery bank positive cable and plugged the converter power cord back in.  The voltage measured 12.68 VDC.  We decided to leave it this way and check it every couple of hours.

The RV technician who does work in the park stopped by and talked to Jeff for 5 minutes.  He said he would order a new converter and schedule them for service on Wednesday, April 9.  Apparently he presumed that Jeff and Kathy were being taken care of in the meantime as he offered no assistance or suggestions for how they might keep their rig functioning for the next five days.

Over the next four hours the voltage gradually dropped to 12.45 VDC, strongly suggesting that the converter was not maintaining the charge on the batteries.  Just before dinner we unplugged the converter 120 VAC power cord and reconnected the 20 A battery charger.  Later at the fire pit Kathy mentioned that the air-conditioners had stopped working so I walked over to check the situation.  I found the battery charger set incorrectly, so I reset it, but I was not able to get the HVAC controller/thermostat to turn either unit on.

We spent the rest of the evening at the fire pit talking and enjoying Smiity’s music.  Our friends from Ontario, Jack, Silvia, Doug, and Paulette came for a while and Smitty did quite a few Gordon Lightfoot songs.  (I don’t know if Canadians like Gordon Lightfoot more than anyone else.  He is certainly one of our favorite singer/songwriters.)  Kathy brought down a couple of bottles of Moscato as a thank you for helping them with their electrical problem.  That wasn’t necessary, but I certainly appreciate it.  Charles and Sandy joined us for a while.  They have relocated here from Texas and are looking to buy a business and settle in.

By 9:30 PM it was just John, Ali, Linda, and me.  John has assumed increased volunteer duties at WCRVR from April 1 through November that include closing up various buildings at night.  I spread the fire logs out on the grate and we returned to our rigs while John attended to his chores.

 

2014/04/03 (R) Electrifying

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Two days ago Jeff and Kathy’s Fleetwood Bounder developed a problem with its 12 VDC house electrical system.  From the symptoms Jeff described it appeared that the AC-to-DC converter may have developed a problem.  Several people stopped by to help so I backed out of the situation.  Too many cooks, etc.

We were gone all day yesterday so I did not have a chance to check with Jeff to see if anything got resolved.  He stopped by our coach this morning to see if I could come down and have a look, so that answered my unasked question.  There is a RV technician who services many of the rigs in the park.  He stopped by briefly yesterday and said he would be back, but had not made it back yet.

The Bounder is equipped with conventional RV appliances for heating, air-conditioning, and refrigeration as well as low voltage DC lighting.  Some appliances operate on propane, some on 120 VAC, and some on both (selectable).  What they have in common is that they all require 12 VDC to operate their control circuits.  If the DC house voltage is not high enough none of these appliances will work.

Failing house batteries would be one possible cause of a DC house voltage problem.  A failed AC-to-DC converter would be another.  A main function of the converter is to maintain the charge on the house batteries which act like a large capacitor in the system and can supply 12 VDC power (for a while) when then rig is not plugged in to shore power and the auxiliary powerplant is not running.  Without the charger function the energy stored in the battery bank will be used by the various appliances.  As the state of charge drops so does the voltage.  Eventually the voltage drops low enough that the appliances will not work.

Jeff had already disconnected the ground cable from the chassis/starting battery, removing it as a load on the converter output.  We turned off the shore power and then disconnected the ground cable from the house battery bank, which consists of two 6 VDC deep cycle batteries in series.  I checked the voltage of both the chassis battery and the house battery bank; both measured 11.5 VDC.  A fully charged “12V” battery with no load and no surface charge measures 12.6 VDC.

I had Jeff turn the shore power back on and measured the voltage across the two house batter cables (with the ground cable still disconnected).  It measured 4.5 volts.  That was obviously not going to charge the battery bank or operate the appliances, but it was odd and not what I expected.  I thought it would be zero, indicating a total failure of the converter.

We left the ground cables off of both the chassis battery and house battery bank.  We connected Jeff’s small battery charger (6 A) to the engine battery and borrowed John’s 20 A charger to charge the house battery bank.  After a couple of hours the house battery bank was up to 12.4 VDC; not fully charged but apparently accepting charge.  Ditto for the chassis battery.  The refrigerator, however, had lost most of its cold and we needed to get it turned back in.

We decided to leave the shore power to the rig turned off so the converter would not be energized, plug the refrigerator AC power cords directly in to the shore power pedestal, and reconnect the house battery bank ground cable to supply 12 VDC to the refrigerator control module.  This allowed the refrigerator to run on 120 VAC and the 20 A battery charger to act like a converter and continue to charge the house battery bank while we figured out what to do next.

This makeshift arrangement worked but was intended to be temporary.  What I really wanted to do was get the converter disconnected so we could restore 120 VAC shore power to the motorhome and not have a faulty converter causing problems.  Up to this point, however, we had not been able to physically locate the converter.  The AC breaker panel did not even have a circuit breaker labeled for the power supply to the converter.

I examined the point of entry for the shore power cord and decided the converter had to be somewhere in the driver side rear of the rig.  The bedroom is located in the rear of the motorhome and that corner of the interior is the shower.  Just forward of the shower is a built in dresser.  The toe kick had a grill that I originally took to be a heat register for the furnace.  It seemed likely, however, that the converter might be under there as this area is directly above the bay where the auxiliary power plant is installed and both the DC and AC distribution panels are close by.

We figured out how to remove the two large lower drawers and there it was, along with the AC power transfer switch.  The converter was a WFCO-8865 rated at 65 A. It was plugged into an AC outlet box on the floor of the cabinet and had two large DC output cables and a chassis ground wire.

I unplugged it, disconnected the DC output ground cable, and taped the exposed conductor to prevent a short circuit.  Jeff restored the shore power and we figured out which circuit the outlet box was on; a 20 A circuit breaker marked “small appliance.”  I plugged it back in and measured the voltage at the converter DC output terminals.  13.5 VDC.  Again, not what I expected to see.  It turns out that I think the reason I was seeing 13.5 VDC may have been that I was looking at the battery voltage.  The case of the converter is bonded to the chassis and so is the  negative terminal of the house battery bank.  Apparently the DC negative connection on the converter is also bonded to the case.

While I was disconnecting the DC negative cable from the converter I discovered that the end of the red (DC positive) cable was not secured properly at the converter and could easily be pulled out.  Yikes!  That could account for the 4.5 VDC we saw earlier at the battery end of the cables.

In order to make their rig as usable as possible I unplugged the converter, plugged the refrigerator 120 VAC cords back in to their outlets, and left the 20 A charger connected to the house battery bank to act as a temporary converter.  With any luck  they were able to use any of their AC or DC devices through the evening and overnight hours.

 

2014/04/01 (T) No April Fool

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Today marked the one year anniversary of Linda’s retirement from Metropolitan Baking Company where she was the controller/treasurer and HR person for 10+ years and the outside CPA for many years before that.  She is still working for the bakery as a consultant, which was part of the reason for her return to Michigan in late February, but she has also been learning how to be retired over the course of the past twelve months.

Carriage Travel Club members. How to tow a 5th wheel RV in style!

Carriage Travel Club members. How to tow a 5th wheel RV in style!

This is now the 5th month in which I have been continuously away from “home” even though the number of days is less than 120 and will only be 126 to 129 days by the time we return to our house.  That may be the longest I have ever been away from a fixed/permanent residence in my life.  The only time that would come close to that was my first year in college when I lived in a dormitory for the school year.  Even then, it was two semesters with a break in-between, and the semesters were only about 14 weeks in duration as best I recall.

Carriage Travel Club banners. They have ~70 rigs at WCRVR all week for a rally.

Carriage Travel Club banners. They have ~70 rigs at WCRVR all week for a rally.

I was reading a post in Nick Russell’s Gypsy Journal blog the other day where he provided answers to FAQ’s he often gets from readers.  One of them had to do with the definitions of “full-timer” and “extended-timer.”  As Nick pointed out, there are no official definitions, but common sense (and usage) suggests that full-timers do not have a fixed dwelling to which they can return while extended-timers do, even if they are rarely or ever there.  How much time do you have to spend in your RV (land- or water-based) to be an extended-timer?  Again, there is no definition, but common sense (and usage) suggests that it is more than 3 – 6 weeks’ vacation usage and less than full time.

Since Linda retired one year ago today we have spent the following time traveling and living in our converted motorcoach:

  • 59 days – (early Jun to early Aug). MI, IN, IL, IA, SD, WY, MT, ND, MN, WI, MI.  Two rallies in Gillette, WY (FMCA and SKP) and a 2-week SKP HFH build in Sheridan, WY plus visits to national parks;
  • 6 days – (mid Aug). Clio, MI GLCC/CCO Back to the Bricks rally;
  • 10 days – (mid Sep) MI, IN, MI Twelve Mile, IN and GLAMARAMA13 rally in Goshen, IN;
  • 12 days – (mid Oct). MI, OH, KY, TN, VA, WV, OH, MI. SKP Photographers BOF photo workshop/rally in Townsend, TN.  GSMNP and camping with family in VA;
  • 103 days – (Dec 19 – Mar 31).  MI, OH, KY, TN, GA, FL.  Mostly in north central Florida; our first season as snowbirds.

That’s 190 days; more than half of the last twelve months.  We don’t have a numerical target, but our sense of how we want to blend RVing with living in a fixed house is to be in the RV for 6 –  8 months out of any given 12 month window but probably not gone for much longer than four months at a time.  It won’t always happen that way, of course, but on average that seems like a comfortable balance to us at this time based on our limited experience and current circumstances.

While going back and forth to the laundry building I stopped and chatted with Jeff for a while.  It appears they have developed a problem with the 12VDC house system in their motorhome.  They noticed it the previous evening as a diming of their lights and then realized the refrigerator did not want to work, even on propane.  I mentioned that we had just had a refrigerator problem and had stored our food in the refrigerator in the Activity Building kitchen while we got it sorted out.  I suggested how he might go about isolating the problem but did not jump in to try to solve it as there was another guy there also giving advice.  Too many cooks creates more problems than it solves.

We went to Satchel’s for an early dinner; our final opportunity to enjoy their excellent vegan pizza.  In addition to John and Ali we were joined by Kevin, Sharon, Ian, and Pat.  We had essentially the same pizza as before; hand-tossed thin crust with pesto base topped with mushrooms, onions, and sun-dried tomatoes.  Instead of the Daiya non-dairy cheese, however, we had the cashew cheese.  Instead of being shredded and evenly spread around the pizza it was in quarter-sized chunks like small mozzarella balls.  It resulted in a different pizza, but it was just as good as the other pizzas we have had there.  I also had the ginger pop.  They make it in house from real, fresh ginger.  The last time it was a bit weak, but today it was the best yet.  The ginger was so strong that burned slightly.  Exquisite.

Work continues at WCRVR on refurbishing the Pullman train cars.

Work continues at WCRVR on refurbishing the Pullman train cars.

The weather had been perfect all day so after we got back we sat around chatting with John and Ali and were joined by Jack and Silvia who were just finishing their evening walk.  We had a small glass of Trader Joe’s Pinot Grigio.  This is one of the wines Trader Joe’s sells for $2.99 a bottle. Our assessment was that you get about what you pay for, but in all fairness Pinot Grigio is a wine we normally drink with a meal, not as a before or after dinner drink.  We were also having grapes for “dessert” and their sweetness probably made the wine seem dry by comparison.  I do not care for dry wines, especially as a before or after dinner drink.  We will try the rest of the bottle with a meal and see if our first impression was off base.  We would love to find a $3 wine that we really like.