Generator Death and Resuscitation: Part I

As you all know, we’ve had some system problems with our ‘completed’ conversion. I guess that is to be expected as many a new big $$$ motorhome spent their first six months of ownership ‘in the shop’ and ours is certainly not one of those!  However, of all the systems, I could always count on the diesel generator; stone-reliable – until it wasn’t.

I wish it had just quit, but I was not to be so lucky. In fact, it ran great!  It powered the lights, the A/C units worked, microwave, all was good but for the fact that my inverter decided to no longer talk to it. I’ve got a 700+ AH battery bank of expensive AGM’s for the house side and they were not getting charged. That’s a problem if you’re dry camping for a week in July, in Louisville, KY, at the annual National Falcon Club of America convention and it’s not a vacation for everyone. Certain amenities are expected…

Now the inverter/charger worked just fine – on shore power, but it would not ‘synch’ to the generator output and no matter how many times I tried (the same thing – see definition of insanity) they would not play nice. So, I knew I had a problem, but where to start looking?

I decided to focus on the generator as it is more ‘mechanical’ thus a better fit for my skills. Yes, it could be the inverter but I decided to hope for the best – lacking a degree in electrical engineering!

I’m back home from Louisville and sooo glad I still have my shop!  So, the first tests revealed  that the generator was just not producing enough voltage, especially under load. Tech support recommended a bigger capacitor to increase voltage, but was unsure about the proper size. “Just try one a little bigger and see if that works.” Ok, they’re the experts and it’s off to Grainger’s for a capacitor just a teeny bit bigger.

This time I had lots of voltage!  138 Volts AC no load and 120 under load! Yay, problem solved! Not!

Now, my nice, expensive automatic transfer switch that allows shore power vs. generator power into the electrical panels suddenly shuts down. Great!  Now I have power at the generator, but the transfer switch won’t let it in! Of course, everything works great on shore power.  One step forward, two steps backward.

Long story short, after several weeks, many calls to tech support at various vendor, and two new circuit boards in my transfer switch I figure out that I’d fried the diodes in the transfer switch circuit board. Yes, 138 V AC was too much!  The old capacitor goes back in and I’m back at square and down a few hundred $$ to boot.

“Maybe it’s something real simple” I think to myself hopefully. Trouble is I don’t know beans about generators so it had better be something REALLY simple. I call one of my bus buddies; our conversation goes something like this:

Did you check the frequency?

What’s that?

The hertz reading on the output voltage.

No, how do I do that?

With a multi-meter!


It’s low.

Then bump up the rpms.

How do I do that?

Adjust the governor.

Where’s the governor?

It’s right there on top.

How much do I adjust it?

Until the hertz reading is right.

OK, at least I know it’s supposed to be 60 hertz here is the U.S. of A.

Adjustments are successfully made and the hertz reading goes to 62 no load and a steady 60 under load. Slam dunk!  Not so fast. The inverter still doesn’t like the kind of language the generator is using…

I decide I need professional help. Yes, that kind also, but I also need a generator expert! Several weeks go by and I’ve found the expert, delivered the bus and the verdict is in: Yep, you’re right there’s something wrong. Turns out the neutral circuit is gone, nada, non-existent. Your generator is DOA and it can’t be fixed.  Prepare to dig deeply into your pocket.

Several more weeks pass while I research new generators, rebuilt engines, etc. A whole new genset is nearly 6 grand and a DIY is nearly as much. Lucky for me (oh, I’m feeling so lucky!)  I found a friendly Kubota dealer and had my little Kubota diesel checked out.  Compression is a little low, but other than that it’s solid. Ok, I don’t need an engine I just need to replace the generator end. Cool!  Another couple of weeks pass as I research a new generator head. That should have been straight-forward, but the generator is old, the bay is small and I’ve got to find a generator that will fit the Kubota AND fit into the bay. Not so easy to do and lots of measuring, drawing and essentially driving the vendors crazy with phone calls and questions – I can be rather obsessive.  Oh, did I mention the bay is not only short and shallow, but vertical space is very limited too.  I settle on an 8 Kw unit and place the order.

Now the fun begins. While this genset was reliable, I was never happy with the way it was installed and I dreaded the day when I would have to work on it. That day arrived and I decided the only way to proceed was a total overhaul of everything. That should not surprise those of who know me – I can’t do anything just ‘good enough.’ It has to be done to the hilt, to the max, the whole nine yards… and I had big plans: a slide, a squirrel-cage fan, sound insulation, easy access for maintenance, auto-start, more amps – the sky’s the limit!  I got close too. I had to give up the slide for reasons I’ll reveal later.

PART TWO Coming Soon: The Old Generator


One comment on “Generator Death and Resuscitation: Part I

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s