Monday, July 29, 2013

Not such a bad day

Its a cliche but that doesn’t make it any less true.  The only good that comes out of a funeral is the reunions that happen as a result.  So it was on Saturday when we buried father’s ashes.  In the morning RJ and Michael arrived from Medicine Hat.  Marlan is somewhere in Montana pushing a combine crew so we didn’t expect him but we weren’t sure that any of the boys would arrive so that made their appearance all the more special.

When we drove into the Wesley Church parking lot there was a white MCI sitting on the north end of the lot.  Marilyn said “I think that’s Papa Bus”.  I said “No way, how would they even know about this?”  But sure enough, it really was Papa Bus complete with Mark and Donna.  After that it didn’t really matter what happened – it was clearly going to be a good day and it was.  We finished it up with a BBQ supper at Dyer Straits and yesterday morning we had breakfast with Mark and Donna before they headed home to Brandon. 

Then I made a quick trip into Regina to get a bolt for my ongoing repair saga on the Onan.  I’m generally pleased with my Onan gensets – it would be hard for them to ever be worse than the effing Kubota that we lived with in the early bus years.  For the most part the Onans work but they’re 30 year old pieces of cast iron that we use sporadically so its not surprising that they occasionally have “issues”.   If you haven’t been paying close attention you may not remember that we have been fortunate enough to end up with virtually identical gensets on the bus and the boat.  The only difference between them is that the one on the boat has a water jacket while the bus version is air cooled.  Otherwise the engines, control systems and generator heads are identical.

On Sunday morning the issue I was dealing with was a leaky fuel filter.  For some reason I thought I had seen fuel leaking from the lip of the filter where it seals to the housing.  Its an old style filter with a bolt through the top of the housing into the filter so I first tried tightening the bolt but that made the leak worse.  Eventually I discovered a tiny hairline crack in the bottom of the filter.  Thanks to a moron at Cummins Mid-Canada (the Onan dealer in Regina) it took a long time to get a filter but on Friday I finally picked up a pair of new filters and they looked like the right ones.  However when I tried to install the new filter it turned out that, while the filter was correctly sized, the bolt hole in the centre was not the same as what I had on my engine.  Closer examination revealed that the mad Ukrainian who built this genset likely just grabbed what he had for a filter off the shelf and found a conveniently sized bolt.  The hole in the filter housing was clearly sized for a much larger bolt than what he had used so, while I had the correct filter for my engine, I couldn’t attach it.  Fortunately Rona had a fine thread 7/16 bolt in the right length to attach the filter so I got that project wrapped up and we headed out of the city. 

On the way out of Regina we finally found a truck wash.  They’re getting increasingly difficult to find, likely because of environmental crap around dealing with their waste water.  The back of the bus was a snotty mess from all the coolant and diesel fuel that we have leaked out over the last year but now it looks good again.  Its also now possible to work on the engine or genset without getting completely filthy.  That almost immediately became important.

We had planned to stop at the Arm River rest area which is on #2 highway just north of Bethune but when we got there the gate was locked.  I suppose its not worth the RM’s time to maintain it but we’ll miss the place – we’ve eaten lunch there several times and overnighted there on occasion.  We ended up parked on the street in Liberty for lunch and then discovered that, while the generator would run with its new filter installed, it wouldn’t make any power.  Oh joy.

When we got to Manitou Regional Park I annoyed the neighbours with genset noise while I tried to troubleshoot my no power situation.  It was actually making power but with wild voltage fluctuations – pegging my needles in both directions on both legs.  It took me a while to figure out which generator end we have – there’s two completely different technologies used on these old girls – but finally I concluded that we have a YD series end and I found a troubleshooting manual for that head.  From there it was pretty obvious that the problem was somehow related to a voltage regulating board that sits on top of the genset.  Its well hidden but I managed to get to it without having to remove the generator from the bus.  As a side note I was very pleased to discover that we have the brushless technology which means no need to mess with replacing brushes or cleaning slip rings.  Not that I had wasted a bunch of time worrying about it anyway but now I am completely absolved of any need to worry in the future.


If you look closely at the photo above there’s two little blue adjustable pots in the lower left.  One of them adjusts the output voltage and the other damps fluctuations in that output voltage.  So I was all set to try adjusting the damper pot although it didn’t really make any sense that it would have suddenly changed.  The voltage has always fluctuated on this generator but yesterday the fluctuations were so wild that the auto transfer switch wouldn’t switch over to generator power.  The transfer switch has some circuitry that waits for the generator output to stabilize before it transfers power and evidently that circuitry never concluded that our power output had stabilized, which it clearly hadn’t.

Anyway, I had Marilyn primed to watch the output needles inside the bus & I was going to at least try adjusting the damper pot.  I had little enthusiasm for my prospects of success but I reasoned that I had nothing anyway so it was hard to see how I could make things worse.  As I was reaching in to adjust the pot over the running genset I happened to notice a very tiny spark on the board.  “That can’t be good” thinks I.  So I watched it for a while and sure enough there was a fairly regularly timed very tiny spark down near the lower right hand corner of the photo.  There’s a couple of what I think likely are wire wound resistors down there and one of them appeared to be a little loose on the board. 

Much later, after I had removed the board, I figured out that the solder trace on the back of the board was actually broken below that loose resistor and had broken loose from the board as well.  That may have been a result of my mad Ukrainian buddy only putting 3 of the 4 mounting screws in the board since the broken solder was very close to the missing screw.  I don’t think this generator vibrates any worse than any other genset but it does vibrate and a circuit board with a corner loose sitting directly on top of the genset is going to jump around a bit too.  Sure enough, when I re-soldered that trace and put everything back together we once again had a working genset (FYI I did find a screw to replace the missing one).  The voltage still fluctuates like it always has but at least now its stable enough for the transfer switch to cut in.  I think I should probably replace the board and there is an aftermarket version available but on the other hand its working so maybe I should leave it the hell alone.  That’s certainly the cheapest option – at least in the short term.

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