8/1 marathon run

[ChrisOlson]

Did you get one of them new shorter ones when your first one hatched?

The voltage those things "see" is bogus.  I got my SW+'s set for 33.0 volt kickout and when I still had the AIMS hooked up it would kick out at 30.3, as shown on the Xantrex for actual battery voltage.  When I got my new Surrette bank I had to give up on the AIMS and retire it.  I absorb those batteries at 30.0 and it wouldn't stay online during absorb.
--
Chris

[BruceM]

Hi Chris,
I hear you on the bogus specs and poor quality of the AIMs unit.  Sometimes a bargain isn't. I read a good article by an engineer who reverse engineered a cheap 12V inverter to see why it worked so poorly. He was not surprised by the time he was done.  It was a poor hack of someone else's design, by someone who didn't know what they were doing.

The Trace designed (bought by Xantrex) SW series sine inverter/chargers are an outstanding piece of engineering. They got a patent for their ingenious low frequency design using 3 big transformers. They had a microprocessor controlling 3 H-bridges on the input (primary) side, giving them 27 steps on the out (secondary) side.  The secondary side are just wired in series to sum the three.

I don't know if the Xantrex products currently being sold as "SW" series are the same, that may be marketing slight of hand.  But the tip off would be the weight; the original had 3 big transformers, and at near 60 Hz frequency, that makes for big transformers.  

Here's a link to a very nice history of inverter design basics by a Trace company engineer.
http://www.dieselduck.ca/machine/04%20auxiliary/2000%20Inverter%20technology.pdf

[fabricator]

Did you get one of them new shorter ones when your first one hatched?

The voltage those things "see" is bogus.  I got my SW+'s set for 33.0 volt kickout and when I still had the AIMS hooked up it would kick out at 30.3, as shown on the Xantrex for actual battery voltage.  When I got my new Surrette bank I had to give up on the AIMS and retire it.  I absorb those batteries at 30.0 and it wouldn't stay online during absorb.
--
Chris

Yep one of the shorter ones, hey no argument on the quality, I'm still workin towards a XW4024, first I gotta upgrade to 200 amp service here, I got absolutely no room for another 220 breaker to run to the XW, the 200amp upgrade should be happening soon, the electricians all set, it's just getting the borg to cooperate.

[ChrisOlson]

Here's a link to a very nice history of inverter design basics by a Trace company engineer.
http://www.dieselduck.ca/machine/04%20auxiliary/2000%20Inverter%20technology.pdf

Hey Bruce, thanks for that.  That was an INTERESTING read!

The new ones are XW-series and they have continued using the same basic design as the SW's.  The only difference now is that the XW-series has 240 split phase built in, without having to stack inverters, and it has auto-load balancing built in.

I got my SW Plus 4024's brand new, still in the box, with a T240 balancing transformer to keep them leg balanced, a Trace ALM (Auxiliary Load Module), a Trace GSM (Generator Start Module), and AC Conduit Boxes for both units.  Those SW's will deliver 14.4 kW (60 amps @ 240 volt) for 10 seconds, and will easily carry 9 kW of continuous load long enough for the master to start the generator and bring it online for Peak Load Management.

The day one of my AIMS inverters blew and the power went out my wife went ape over it.  I got explicit instructions on how to get in the truck and go buy some decent inverters.  I went to a brick and mortor RE store with the idea of getting twin Outbacks.  When I told the guy all my wife wanted, he just said, "Nope - won't work.  You need these."  "These" was the above described equipment sitting on a pallet in the warehouse.  He opened up one of the boxes so I could see.  I was going to spin the box around to take a better look and it wouldn't move.  I kid you not, I looked under the pallet to see if it had concrete anchors going into the floor or something.

It took three men to lift each one of those units up and get it bolted to the wall.  But holy crap, what a difference.

You try to get 4 kW continuous for more than a minute from one of those AIMS "5 kW" inverters and it overheats.  I had mine apart when it blew the last time and they only 10 gauge wire feeding the "full power" AC terminal block on it.  I thought they were pretty good.  And they replaced them under warranty every time one blew up.  But otherwise, they are pretty weak.

I been on this forum for a long time but just read it mostly.  I been watching Dale's Lister being used for a CHP unit here with great interest.  I don't know how many hours one is good for before it needs overhaul, but it's pretty cool and I like the concept.
--
Chris

[fabricator]

Yeah and now you got me dreaming increased oil capacity and circulation, like I need another project.

[BruceM]

Thanks for the good info, Chris. It's good to hear Xantrex didn't get rid of the basic Trace SW design. I noticed they are selling high frequency sine models now too, I guess the pressure to make smaller, cheaper units was irresistible.

Alas, there's no SW series for 120VDC, unless I roll my own, much simplified version.

[fabricator]

there is a new wrinkle in the marathon run, it's now running on centrifuged and dried waste veg oil.
this is the veg tank with the thermosiphon tank below it.

I ran 3/8 OD copper from the veg tank into the water tank and have about 20 feet in a coil at the top of the tank.

Then I ran the copper inside the upper hose down to the engine.

What you see there is a compression fitting that I drilled out and ran the copper through it, it worked great.
This is an overview of how it tees into the fuel line, it's now all insulated.

I'm gonna get a smaller fuel filter, the big one holds too much oil and lets it cool down some, the switch over was seamless, it never even stuttered just kept running nice and steady.