Two inverters for 50 amp service

[Cptnvideo]

We have a Go Power IC Series 3000 watt inverter and 50 amp service on our 5th wheel. I have 2 complaints about it that I wasn't aware of when it was installed.
The monitor panel only monitors Line 1. The current limit function only limits current on Line 1. So when plugged into a relative's 15 or 20 amp service, we can only see and control what is being drawn on Line 1. And I would like to control the current on both lines so we wouldn't inadvertently trip the breaker feeding the RV.
Is it possible to have two 2000 watt inverters (one on each line)? My dealer says no. But I don't see why not as nothing in the RV runs on 240 volts.
Correct me if I'm wrong, but to create 240 VAC for two 120 VAC lines, the 2 lines have to be out of phase. And if the lines were in phase, 0 VAC would be measured across the 2 lines. So the output of the 2 inverters would be out of phase when plugged into a 50 amp service and in phase when plugged into 30 (or less) amp service. But I don't see an issue with that. Am I missing something?

[CA_Traveler]

Are you sure a 2KW inverter will be adequate for your 13A A/C considering startup surge amps?

[pianotuna]

Cptnvideo wrote:
Typing while you posted, CA. Oops.
With the load sharing on each line, I will be able to run 18 amps worth of "stuff" on 15 amps of shore and not have to worry about tripping a breaker inside a friend/relatives home. Which to me is a little embarrassing.

Hi,

I'd suggest 13 amps as a "cap" for a 15 amp shore connection. i.e. 80% of 15.

[Cptnvideo]

Typing while you posted, CA. Oops.
With the load sharing on each line, I will be able to run 18 amps worth of "stuff" on 15 amps of shore and not have to worry about tripping a breaker inside a friend/relatives home. Which to me is a little embarrassing.

[Cptnvideo]

"Personally I don’t like what the Cptn wants to do but he’s gotta do what’s best for him."

Why, CA? All I want to do is have load sharing and monitoring on L1 and L2 instead of just L1.

[CA_Traveler]

Cptnvideo wrote:
Good points, wa8. I'm thinking about replacing the 3000 watt inverter/charger with 2 2000 watt units. Then using L1 of each so that I have monitoring and load sharing of both L1 and L2.

OK I didn't even consider that you would connect both inverters to one hot considering that you wanted to monitor each hot line with the inverter display.

[Cptnvideo]

Don, not sure of the terminology but I guess the GoPower IC series is a hybrid. They are inverter/chargers with load sharing and a remote monitor/control.
I never use the charger portion unless we're boondocking and need to charge the batteries with the generator (happened twice).

[CA_Traveler]

I don’t see that as a problem at all. While on shore power the 2 inverters are synchronized. If not on shore power the 2 inverter outputs are derived from the batteries and not the inverters AC inputs.

What is not been made clear is that each A/Cs AC input must be directly connected with a CB to its inverter AC output bypassing the RV CB panel. Hence the A/Cs will always use the inverter unless an appropriate switch (DPDT) is included. Why? On shore 20A and 30A the two hot lines are connected/shorted and hence if the ACs were connected to them it’s a direct short across both inverters. And with 50A there is 240V across the 2 hots.

Personally I don’t like what the Cptn wants to do but he’s gotta do what’s best for him.

[Cptnvideo]

Good points, wa8. I'm thinking about replacing the 3000 watt inverter/charger with 2 2000 watt units. Then using L1 of each so that I have monitoring and load sharing of both L1 and L2.

[wa8yxm]

Cptnvideo wrote:
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.

The answer to that is rather complex and involves the neutral line
With two inverters it is possible that if they are not properly phased the neutral could be carrying way more current than it is designed to haul.

120/240/120 volt Power. like a house.. Current flowing in both legs does NOT flow in the neutral So if you have say 1,000 watts of load on L-1 and 1,500 watts load on L-2 the neutral is hauling only the current from the difference 500 watts or bout 4.1 amps. But if you have two 3,000 watt inverters is 6,000 watts or 50 amps.. that's the maximum for the neutral line.. I don't like maxing out wires.

[pianotuna]

Hi Bill,

So the Go Power inverter is a hybrid unit?

There is also the option to do old fashioned double conversion.

I used to plug only the converter in, and run the RV off the inverter.

Then I got a hybrid inverter/charger with load support.

[Cptnvideo]

Just got a call back from a GoPower engineer. Yes, I can do exactly what I want to do.
Example: I'm on 15 amp shore power. I want to run 2 ACs for an hour. I limit the shore to 7 amps for each line and the ACs are on separate lines. AC draw is 10 amps per line. The inverters supply the remaining 3 amps each or 60 amps out of the batteries.
Side note. If I had bought a smaller RV with 30 amp service, none of this would be an issue.

[CA_Traveler]

I believe we both were implying that an EMS is an additional tool.

[Cptnvideo]

Michelle and CA, what you propose would not let me "share" the load between shore and batteries like the GoPower IC does.
CA, with load sharing between 15 or 20 amp shore and batteries supplying the additional current to the inverters, I can run 1 or 2 ACs, just not for an extended period of time.

[CA_Traveler]

Michelle.S wrote:
Simple, install a good EMS that has a remote display of both legs L1 & L2.
I have the Progressive Hardwired EMS and know exactly what the voltage and current are on each leg.

X2

[CA_Traveler]

Cptn: 50A 120/240V service is SINGLE PHASE POWER the same as the typical house. Granted many think it's 2 phase, it is not and cannot be because it's a single secondary winding on the transformer and the center tap is the neutral. And yes it's 240V across the 2 hots.

You can install a load sharing inverter on each hot line with battery input. The 120V output of each (or at least one) will need to be connected directly to a A/C and not through the main CB panel.

Running one A/C on a 20A circuit can be iffy especially in a CG as the voltage will often be low. 1600W solar will yield about 1000W on a normal day unless you have tracking solar. So you can get some limited A/C run time when there is sun, no other significant loads and not so much when the sun doesn't shine.

You have more solar than most but is it practical for A/Cs? Probably best to use a gen for the A/Cs unless you have 30 or 50A shore power. All of this gets moderated depending upon the weather so roll the dice for any particular day and night.