On Sun, 06 Mar 2005 15:40:01 -0800, Walt Bilofsky
wrote:

Has anyone had experience trying to drive a Xantrex inverter/charger
with a small gas generator?

The specs for the Xantrex Prosine 2.0 inverter/charger say that when
it's plugged into shorepower (or an external generator), it will
automatically reduce the charger load to keep the AC source voltage
above a minimum level.

If that's to be believed, I should be able to run a portable 1 KW
generator into the Xantrex, and have it draw as much current as the
generator can serve up, but not overload it. I should also be able to
have AC appliances running off the Xantrex, and still charge the
battery with any AC power left over.

Has anyone actually done that? Or had any experience with that kind
of setup?

- Walt Bilofsky

Read the manual for your inverter/charger CAREFULLY _before_ buying
the generator.

I have a TrueCharge 40 which a simple calculation says can be easily
driven by a 600 watt generator - so I bought a Honda 600W generator.
The charger trips the breaker on the generator every time I try it,
because that (and probably most similar chargers) have an awful power
factor - the charger actually draws about 8.5 amps at 120V, while the
40 amp at 12 (more like 14) volt output suggests that it should take
560 watts or 4.7 amps.

The TruCharge 40+ has no provision to limit the input current - don't
know about the ProSine.

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
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Peter Bennett wrote:

snip

The TruCharge 40+ has no provision to limit the input current - don't
know about the ProSine.

Peter, the manual says:

"The ProSine 2.0 uses a Power Share feature which senses the AC load
on the system and gives priority to your AC loads, thereby reducing
the charger current ... Sometimes the usual AC shorepower sources have
a low voltage. To avoid loading these weak sources any further, the
charger automatically reduces its AC current draw as the AC voltage
approaches the minimum acceptable level (as set by the user)."

Sounds great in theory, and the ability to set the triggering AC
voltage level will give some ability to tune the system. But as Wayne
says, there might be a surging effect - especially if the generator is
running when the air conditioner compressor goes on.

That's why I'm looking for people who have tried this sort of thing.
It's a bit hard to breadboard up a system without making a major
investment in at least some of the components.

- Walt Bilofsky

Peter Bennett is absolutely correct. Inverter/Chargers run at .5 to .7 power
factor which means that the AC current supplied to them will be as much as
double what the calculation of DC volts * DC amps= DCwatts/115 AC volts
gives you. It is current which trips out a genset. It is power (watts) that
overloads its engine.

The Honda EU1000i is only rated for 850 watts continuous, so it could just
barely (as Larry notes) run a 5000 BTU, 7 amp Carry On. I am rather
surprised that it even starts it, as the inrush current is at least double
the 7 amp running current. Chalk that up to the excellent electronics in the
little Honda. I had a 2800 watt Coleman generator that would barely start a
Carry On. And as Larry noted with the Honda, it wouldn't restart it unless
the freon circuit stabilized its pressure over quite a while to eliminate
the high head pressure start up condition.

A better solution is a larger generator or a very efficient charger. IOTA
makes a fairly efficient charger- about .8 power factor as I recall. Even
so, the Honda EU1000i will be limited to supporting a 40 amp DC charging
rate at best.

David