[C320-list] Installing an inverter

[catalina at thehares.com]

Hi Dean,

1) I'm not sure about the startup load on the microwave, but it might need
to be over 2kw peak.

2) The modified sine wave can be done but is not a great idea for the
Microwave, especially if you're only running from batteries. Here's why:
While a microwave will function from a modified sinewave inverter, the
performance of the microwave will be very slow and gets even worse as the
battery supply voltage drops. (e.g. to boil one cup of water on a modified
sinewave inverter might take around 2.5 minutes while drawing around
100+amps DC, compared to around 30 seconds with a pure sine wave inverter
also consuming 100+amps DC).  As your batteries voltage drops, the inverter
will attempt to take more and more current to keep the output RMS voltage
around 110+ AC.

You might be better off getting one of those tiny nearly silent Honda
portable generators like the EU2000i, putting it on the swim platform when
you need AC.  It's less expensive than a sine wave inverter and will solve
virtually all your AC needs under way.  You'll save money as well, but at
the cost of a slight bit of inconvenience to plug in and start the
generator.  Before ruling that option out, you might want to visit a dealer
and hear just how quiet they are.

3) Yes. The closer to the batteries the better, however, you can run heavy
expensive cables (like what feeds the starter) and mount the inverter
elsewhere.  The voltage drop at 100+ amps is significant.

-Jeff
#809 


On Wed, 04 Mar 2009 08:03:30 -0600, Dean Vermeire <dean at vermeire.us> wrote:
> Hi All,
> 
> I'm thinking about installing an AC inverter to be able to run the
> microwave, etc. when not in the marina.  I know a number of you have
> done this.  I've done a little homework, but there is a reason I did not
> major in electrical engineering.  So, I have a few questions:
> 
> 1.  How many watts?  I figure I should have at least 1200 continuous.
> 2.  Are the ones with a modified sine wave good enough?  I wouldn't
> think the microwave would care too much.
> 3.  Where should it be installed?  I've read that you should install it
> close to the batteries, but those are on the starboard side and the
> microwave is on the port side.
> 4.  Any particular brands to avoid?
> 
> Thanks in advance,
> Dean Vermeire
> Moonstruck II (#847)