Scott, not sure which thread you are referring to.
For starters, as wired from the factory:
Shore power in, A & B to transfer switch to EMS to panel box A & B
Generator in, A & B to transfer switch to EMS to panel box A & B
When on either incoming AC source, converter is charging house batteries and EMS is protecting the trailer.
Cyclone transfer switches are wired so that generator has priority, e.g. when on shore power and starting generator, transfer goes to generator, regardless of AC supply.
As you describe above:
Best case scenario with a higher end inverter wired in as you mention will:
Shore power in, A & B to transfer switch to EMS - A to panel box - B - to inverter - to sub panel.
Generator in, A & B to transfer switch to EMS - A to panel box - B to inverter - sub panel.
Genny has priority.
Panel box, "A" circuit is always receiving power from either shore or genny when available
Sub panel, “B” circuit is always receiving power from either shore or genny also.
But - when no outside power is incoming, the inverter instantly switches over to inverter mode, supplying AC to "B" subpanel.
The original converter is disconnected (unplugged) and when on either shore or genny the inverter is charging the batteries and supplying 12 volts to the trailer's 12 volt system.
The better inverters, 2K, 2.5K and 3K by Heart, Trace, Magnum, Xantrex etc are all excellent inverters, instantly switching from source to inverter mode back to source. Odds are if you are not watching an incandescent bulb, you will not see the switchover.
A side benefit with these higher end units is that they also filter-clean the incoming power. So if you add your TVs, computers and other sensitive electronics to the inverter supply you are eliminating or at least minimizing voltage spikes, surges interference etc.
The inverters are available with remote control panels so you can turn them on and off.
Keeping this in mind, if the inverter is “on”, any time you are on outside AC your inverter is cruising along charging the batteries, AC flowing through to the sub panel.
Anytime you disconnect or are not on the genny your inverter is “inverting”, using your batteries.
Cheap inverters run anywhere from 50-70 % efficient.
The higher end units can be well above 80-90%. Now your battery bank comes into play.
Using this example you could, when prepping your trailer to go camping at home turn the inverter on. When you disconnect from the house and hook up to the truck you are now supplying the “B” circuit with your inverter, travel –camp – travel – camp – home etc and your B circuit never lost power, TVs never spiked, coffee pot clock never lost time etc.
Using the above numbers, a 3K inverter running at 90% efficiency will supply approximately 23 amps off a decent battery bank for X amount of time. Odds are though you would be way under the 23 amp draw unless you try running the air conditioner too.
My plans with an inverter, if I ever follow through, will allow me to run the AC off the inverter while traveling instead of using generator to pre-cool. I already have 2/0 battery cables directly wired to the truck’s batteries (one of the reasons I ordered the truck with dual alternators).
I will wire an additional trailer pigtail to feed the batteries from this truck supply.
So, back to your original question:
If i am correct, everything he moved to the sub panel will always be powered by the batteries and never from shore power?
No, always by Shore, then genset then inverter
If wired like that, the EMS would not come into play, right?
No, the EMS will always be protecting from either shore or genset. The inverter does not need that protection with the power it is supplying to the sub panel (assuming the inverter to panel is wired correctly)
One caveat – you cannot run the inverter before the Progressive EMS!
The EMS will sacrifice itself. Don’t know why, but it is in the EMS manual and I can tell you from experience it is correct.
