Two inverters for 50 amp service

Nice post, wa8yxm. But doesn't really answer my question. BTW, neither did GoPower tech support.
Since I don't have any 240 VAC appliances, I don't see why I couldn't have 2 separate inverters and no need to sync them.

Larry, I can see where my post is confusing. We have 1600 watts of solar and 618 ah of batteries.
We might want to run 2 A/C units while plugged in to a 15 or 20 amp circuit. The IC series inverter allows you to limit incoming current, making up the rest from batteries. But it only does this on Line 1. By going with 2 inverters, I can limit the current on each line thereby avoiding tripping the shore breaker. And the inverters will get the excess amps from the batteries.

Ok the answer to "Is it possible to have two inverters for 50 amp service" is.. like the answer the old men gave to the question Boxers or Briefs... "Depends".

Some.. For example when I first got my RV I had an inverter installed. It's no longer made but it was an Xantrex Prosine 2.0... NOW. I only had selected systems on the prosine.. but this model has a port that can be used to "Sync" it with another of the same model to produce 240 volts divided into two 120 volt legs (Same as the power from the park/pole).

That said the Xantrex that replaced it when it died.> DOES NOT HAVE the ability to team with another for 120/240/120 volt operation. I checked the Spec page for the Go Power IC Series 3000 watt inverter and it does not appear to be one that can be paired in this manner.

What do I suggest:
Take your pick of one of the following products and install it in the Shore Power line before the Automatic transfer switch (or alternatively next section)

Progressive Industries HW-50C (hard wired surge protection) WITH REMOTE.
The remote monitors both lines

Southwire/TRC Surge Guard. 34550 With optional remote

Or any equivlant product These are hard wired Surge guards they monitor incoming voltage. Current and in some cases other stuff. they will alert you to open ground or neutral and so on (I put mine before the auto transfer switch so it did not deal with the generator which has a monitoring system of it's own)

The alternatige is the portable version of the same devices.. Some now link to a phone app via Wi-Fi.. But make sure you get the top end units NOT the cheaper ones which do not monitor current... I prefer the hard wired for several reasons,

1 You never forget them as they are always there
2: Outta Sight, Outta mind (of Sticky Fingered type) so they do not grow legs.

The may..howeger...fail.. and thus mine was installed in the manner of the Hughes Autoformer (Look it up) so that if it failed I could physically bypass it. (never happened. though the older portable did die).

Let's start from the beginning: The inverter, no matter what, typically runs with a 12 VDC input. For this part, you can hook up your 12 VDC line to two inverters without any problem.

Second, each of those inverters typically has two each 120V AC single phase lines at the output which would give you a total of four 120vac, 15/20 amp, single phase lines.

Third, you don't have to use all four! For example, you can use one line from each inverter. Use one line to power one side of the RV, and another line to power the other side.

If your inverter has a line monitor that watches only one line, use that line on one side, and use one line from the other inverter on the other side. Both lines would be monitored.

However, since each of the four lines has an individual breaker in the inverter, it will monitor itself anyway.

Kinda expensive. Also, you say you may be plugged into a relative's 15 or 20 amp line. I have to assume this means you are running off an AC line and really don't need an inverter, since the inverter makes AC from DC in.

Two each, 2000 watt inverters in the above suggestion will be able to produce a maximum of 2000 watts since you are only using half of each one. However, those inverters are taking power from your batteries. The batteries have to be charged from the relatives house AC power which is limited to 15 or possibly 20
amps.

A 20 amp AC line from the relatives house can only deliver a MAX of 2400 watts and that is assuming no losses and a perfect condition.

I guess I've talked myself into getting confused about what you really want to do.