Inverter Feedback

[wponder]

Hoping to get some inverter guidance. I decided to upgrade my inverter to try and run a few extra appliances. I wanted to try an make all my outlets run on the inverter 2016 Int. since none of the ones near the kitchen run off the inverter and are the shore outlets. I was going to go with a Samlex PST2000 inverter as I do not need or care about a charger. However, it does not have auto switching. I was hoping for a drop-in solution with minimal wire changes. Seems like I would need to add an auto-swticher to the picture and a subpanel. Is there a better, simpler solution or should I just forgo trying to get all the outlets going.

[wponder]

I should add. I am ok with MANUALLY switching between shore and battery. I am really just trying to get more plugs going though the battery / inverter path.

[wponder]

I think I sorted this out in my head and reading more so just want to verify.

1. Need to get a Pass-Thru capable inverter 2000 - 3000 watt
2. Need to slightly modify the wiring path

From the output of the existing or a new transfer relay wire in a 30A fuse and panel

From the new 30A fuse and panel wire out to the new pass-thru inverter to the 30A on the main

If the new inverter does not have two hardwire options I assume I need to mover the existing hardwired GFCI loop into the main on a breaker

Thanks

[TG Twinkie]

You must have a boatload of battery capacity to run that size inverter.
The DC wire size will be huge. Not to mention the DC fuse size.
This does not seem practical. IMHO

[wponder]

I have excess battery capacity and solar capacity to handle running the appliances for short period loads from a 2K inverter. I'm not trying to run the AC and one issue ( I think ) is the refer being on the GFCI loop. I want to free up some of those GFCI outlets for the other devices so I do not have to move them around. So, I think its in scope.

[SilverHouseDreams]

One thing to consider is that efficiency of a inverter is not fixed, they are usually quoting the peak efficiency. In most cases the further you are from the target output of the inverter the lower the efficiency. So if you normally only are pulling 100W out of a 3000W inverter you are likely at the worst of the efficiency curve, and will actually use far more energy. But, if you have battery capacity to spare and are confident that the sun always shines on your panels I guess you have nothing to worry about.

[SilverHouseDreams]

Also, when you size the wiring I believe you need to account for the efficiency as the inverter is rated on output and not input. This particular inverter has peak efficiency of 85%, so if you draw 2000W the batteries actually are at least 2300W...that’s nearly 30 amps difference.

[wponder]

Thanks #@ Silverhousedreams.... I ultimately decided to ditch on the Samlex as it does not do pass-thru. So many other options out there that do. I ultimately will likely do one with with a charger although I do not need it or care about it. This for short burst loads and all wires DC to inverter and inverter to AC side will be sized right for the inverter and lengths to batt, fuses etc. Need to upgrade my fuse also. Attached are two diagrams how how things are today and what I am going to change it too. I want to repurpose the existing Parallax panel into a sub. I was unsure about how to clearly take the current converter / charger out of the picture to avoid any loops or bonding from occurring. Looking at it closer I see how to do it.

This approach should isolate the AC from the inverter but allow for shore / gen powering it. It re-uses the existing ATS to handle Shore / Gen 30A switching. It moves the existing inverter plugs into the old main panel and opens up all items to be run on inverter as / if needed when on battery. It does not automatically address the fridge on battery.

If anyone has feedback on this not being possible and or its valid let me know.

Thanks!

[wulfraat]

If you are looking for a pass through, hands down look to victron or magnum. Both have their pros and cons.

They both offer hybrid models which is nice as it allows you to run a smaller genset and automatically supplement the generator output with battery to run the AC, etc...

I’m having a victron 12/3000 installed next month. This unit has two AC outputs - one powered by the inverter (to include hybrid power deliver if connected to shore power or an genset) and a second AC output that is only hot when shore power is present. Could simplify your wiring.

[pdavitt]

Most people understand the need for an automatic transfer switch for AC sources. You can only have one active at a time. What is not so well known is the need for Neutral/Ground bond switching. You must have one and only one neutral/ground bond in a system. When shopping for Inverter/Chargers be sure an automatic neutral/ground bond switch is included.

The sequencing of events is also important for safety reasons and to avoid false trips of GFCI and ELCI protective devices. For example Victron Inverter/Chargers have this functionality. Other brands such as Outback and Magnum have it also.

It works like this: You are running on the inverter and turn on shore power. The inverter does the following in order: Turns off the inverter AC output, disconnects the internal neutral/ground bond, then turns on the shore power. When you turn off shore power it then re-connects the neutral/ground bond and turns on the inverter AC power.

Hope this helps,
Pat

[TG Twinkie]

You didn't mean to imply that the neutral and ground are tied (bonded) together in the coach. I hope.
The chassis ground on inverters I have installed is separate from the neutral.
IMHO there is no need to switch the ground.
The neutral and hot leg are switched thru the pass thru function. If so equipped.

[pdavitt]

Only when there is no external AC source active. Shore Power and Generators both provide the neutral ground bond. When an Pass Through Inverter/Charger is in inverter mode the neutral ground bond is established internally. Example drawing below: AC Out 2 is only hot when an external AC source is active.