Yamaha 2000iS and softstart with AC?

If it was me I would more than likely upgrade genny, adding soft start to your AC unit may get it to work at sea level or lower elevations, won't be nearly as reliable as you go up in elevation. With such a nice rig I would go with an onboard Onan so you could run both AC units along with everything else as if plugged into shorepower.

A major plus is you have access to all the power an Onan provides with a touch of a button, no hassle hauling out a portable, connecting heavy cables, getting out of your rig to start/stop unit, and fretting someone doesn't walk off with your genny. Additionally, we often run Onan on hot days to cool rig down before arriving to our destination.

When we wanted to get a portable genny to give our onboard a break, there were many instances where Onan was major overkill for most power demands. We purchased a Champion inverter genny with remote start, nearly as convenient to start/stop as our Onan. That was 5 years ago, powers RV AC unit tested at over 9K', over 300 hours and zero issues.

MNRon wrote:
If I can’t be sure, I’m probably better to invest in a new generator.
Thanks

^^^THIS^^^ Is your answer.

While there have been some folks who have had success in getting a 2KW gen to run a roof A/C unit with a softstart kit there is no way to tell if it is going to work with your typical camping situation.

Per HERE that gen has rating of 13.3A at 120V continuous and 16.7A at 120V Surge current.

Typical 13.5K BTU Roof air will typically have a run current of around 13A but possibly as much as 15A run current under full load per HERE

In that same link, the smallest gen they recommend is a 3.5Kw gen and I would agree with if you want it to work 100% of the time..

Sandia Man and Gdetrailer - thanks for your replies. I don’t have a problem using my battery bank to augment my underpowered generator, my current issue is that the Yamaha 2000iS is so weak that to can’t deal with the surge and puts the system into oscillation. IF I can know the softstart would prevent this I’m good with that solution for the amount of AC we typically require.

With all of that said, I do hear the advice I’m being given and am starting to entertain more seriously. Space and weight (as well as cost) make the Onan solution overkill for our need, but maybe a 3k genny is in my future…

Get a generator of at least 3000w rather than thrash that poor little generator for all it's worth only to have iffy operation.

Look for sales and you can find something in the 3000-4500w range for $600-750.

Looking at the new Champion 4500w inverter for $750 right now.

or get another to parallel with it, if that's possible.

What is your battery situation? You mention having the inverter, and apparently have tried using it. I know others in here have more experience in this than I do, and hopefully one will chime in, but,,,,,
Can you run the AC from your batteries, via the inverter?
If so, can you run a stand alone battery charger from the generator to boost the batteries?
It likely wont keep up, but if you only want a couple of hours a day of use, and dont mind running the Genny for a couple of additional hours to replenish the batteries, you may squeak by.
What I am asking is,,,
IF you turn off the converter
run the AC from the inverter
and then run the genny, powering a separate standalone battery charger, could it work for limited periods of time?

Problem is too large of air cond mismatched with too small of generator…Either way, lots of variables mean soft-starts are a cr#p shoot…JMO

3 tons

THANKS ALL!!

You’ve basically reaffirmed what I guess I knew. I need a bigger generator (or another yamaha2k if I could find one used to parallel). My only hope against this realization was if someone chimed in saying they had my identical setup *with* a softstart and it worked great…odds weren’t great but it could have happened :)

Wanderingaimlessly - I have run my AC off of batteries, but at ~160A when it was hot yesterday it only takes a couple hours to draw my AGMs to 50%…even with 4/0 cables, not sure I want to continually be running that kind of current. A automotive type battery charger in parallel would just be a drop in that bucket.

I’ll have to start looking for gennys, I definitely want a quiet inverter type. Thanks again

Yeah. A larger generator won't have to work as hard as that little 2000.

MNRon wrote:
Wanderingaimlessly - I have run my AC off of batteries, but at ~160A when it was hot yesterday it only takes a couple hours to draw my AGMs to 50%…even with 4/0 cables, not sure I want to continually be running that kind of current.

You don't. Things tend to heat up, cables, connectors, batteries. I run a 48v system with 1/4 the amperage and things still heat up.