Microwaves and MSN

 

Well, my little Honda eu2000i finally wore out after only about 12,000 hours
(well, maybe 13,000).  I was beginning to think it would last forever.
Meanwhile (until I get the engine rebuilt or get a new one) I have to run my
microwave from a 5000 watt generator.  I tried running a little 700 watt
microwave from my Wagan 700 watt MSN inverter and the test water took a long
time to get hot.  The inverter was screaming the whole time.  Are microwave
ovens that particular about the input waveform?  Will I ever be able to make
microwave popcorn again?

At the moment I'm putting together one of those gas engine running an
alternator type chargers and I'm thinking of getting a 1500 watt MSN
(Xantrex maybe) for the microwave etc.  I only have two 220Ah 6V batteries
so I won't be running it very much.  The biggest obstacle right now is Auto
Zone can only look up parts for a particular car so I need a specific part
number for a GM one wire 63 amp alternator with built-in voltage regulator.

I tried running my Vector Smart Charger from a Coleman Pulse 1850 generator
but it will not charge faster than about 13 amps.  It worked great with the
little Honda inverter generator.  I also tried running the battery charger
for a few moments from the inverter that was connected to the batteries it
was charging and it seemed to work fine (of course the inverter was
protesting the stupidity of the whole situation) so I'm thinking that if
it's possible to run the inverter directly from the alternator then I could
go back to 3 stage charging which I would prefer over just charging directly
from an alternator and keeping my eye on it all the time.  And of course it
would have to be connected to the well-charged batteries again to run the
microwave.

If all goes well I should have a $310 inverter generator of around 800
watts.  (Honda 4 hp engine $150, Xantrex 1500 watt inverter $100, pulley
$10, and alternator $50).

 

Um, er, make that MSW.  How many times did I write that?  Time for a nap
maybe.



microwave

regulator.

generator

directly

 

your 700 watt (cooking power) actually pulls about 1000 watts from the
plug, so your 700watt inverter was in surge mode. not good for extended
run times. However, Even on my 2500 watt inverter, though my inverter is
happy, my microwave sounds like someone threw sand in it's gears. It's
definitely a waveform issue. I didn't get a reduction in cooking times.


Steve Spence
Dir., Green Trust,   http://www.green-trust.org
Contributing Editor, http://www.off-grid.net
                      http://www.rebelwolf.com/essn.html

Ulysses wrote:

 

Well not quite correct. Surge would only last for perhaps thirty
seconds. Most likely less before shut down. Most good quality inverters
will have a continuous rating, a half hour rating and a surge rating.

It will be interesting to see if your inverter will run directly from an
alternator. I suspect it will go over-voltage and shut down. It will
depend on how well the reg reacts to the load of the inverter. Let us
know what happens.

Steve Spence wrote:

 



So far so good.  Actually better than I expected and as much as I could hope
for.  I connected a Wagan MSW 700 watt inverter to the alternator (no
battery in system) and it worked fine.  My voltmeter read about 14.5 VDC.
With the engine running at somewhere around 1500 rpm I was charging my
batteries with the Vector charger at about 25 amps and running this computer
(Dell desktop 2.4Ghz with 15" LCD monitor and also ran my inkjet printer)
and the only problem was the monitor winked out momentarily when the Vector
finished it's initial battery check mode, shut down, and restarted.  The
computer stayed on and stayed connected :-D

I also expected that it might shut down from overvoltage and had plans to
add a big fat diode on the power side to drop the voltage a little but so
far it does not seem necessary.  Some kind of buffer to stabilize the
voltage would be a big improvement here.  Got any suggestions?

Now for the hard part: repackaging the whole thing so it's convenient to use
and move around.