T@B 400 Inverter Outlet ?

LSkrabut

On a T@B 400, factory installed inverter outlet, while testing the outlets in my new 400, I found that the inverter outlet is indicating an "open ground" per the plug in tester I have. All of the other outlets are OK.

Wondering if the inverter outlet is intentionally connected this way or this is an issue that needed to be corrected by NuCamp/Dealer?

Michigan_Mike

I'm guessing that the inverter is wired directly to the battery and you basically have a floating ground as it's not connected to an earth ground.   If the trailer is plugged into shore power the existing 120V outlets should test out okay with your tester, but the inverter will show an open ground which I am told is normal.  The plug-in tester is normally used for an AC circuit and I don't believe it will provide accurate read for the inverter.  

Have you tried plugging an item into the inverter using the inverter powered from the battery?   I'll bet everything is fine.  

LSkrabut

Just tried testing without shore power (Yes I turned off Alde 1st, all other devices(Fridge, Jensen's are turn off or unplugged).

No difference in the indicated "Open Ground" from Battery/Solar charging or shore power.

I was also guessing a floating ground, just not sure if that is a correct "assumption" on my part or not.

Michigan_Mike

But your inverter is working, correct???

Plug in a 110V item like a light or something comparable and verify that the inverter actually works.  And do a search on Google too and you will see that this is common and that the inverter is fine.  

LSkrabut

After digging in from some of the internet articles.

There should be only 1 neutral/ground bonding. Since there is an inverter and shore power, only 1 should have that bond when active.

Tomorrow I will check the ground path from the shore power plugs to trailer ground vs battery ground to the inverter plug, then check battery ground to trailer ground, which as I gather should be an open other than for trailer-TV lights, turn/stop and brake.

But that brings up the thought trailer ground should be 12VDC ground also. Since the inverter/solar/shore power can be active at the same time in a parked-shore power situation, but battery should be separate from shore power bond. Hmmm, wondering now if that is why some have notice blown fuses?

davel4wa

I'm not sure what model inverter is installed but if Nucamp did this correctly they would use an inverter with an automatic transfer function. When plugged into shore power the inverter outlet(s) would be switched to shore power and would not be a battery drain. There is some extra cost but probably under $50.

klenger

From my experience, the floating ground on a generator or inverter is not a concern, but some EMS devices will fail to pass power if they sense this condition.  Since it is unlikely that an EMS would be installed downstream from the inverter, it's not really a problem.  I installed a Go-Power 150 watt sine wave inverter in my 320 and had the same issue.  I simply plugged in a neutral-ground adapter (jumper) plug into the 2nd outlet of the inverter and the error no longer exists.  This jumper plug is a common solution for many inverter generators (Honda EU2000i) that cause the same issue.  I find it interesting that the Xantrex inverters do not have this problem, I assume because Xantrex bonds the neutral and ground together inside their inverters.    Here's an example of the adapter, but you can make one yourself by buying a 120 VAC 15 amp male plug and simply add a jumper wire from the neutral terminal (make sure not to use the hot terminal) to the ground terminal.

https://www.microair.net/products/generator-bonding-plug?variant=12272654155860