Jump to content

Inverter Output Configuration

Recommended Posts

This has been discussed below to some extent, but I think this more specific question deserves its own thread.


In the case of Generators or Utility Power I pretty well understand the design purpose and operation of GROUNDED systems which have a NEUTRAL, be it Floating or Bonded etc., and all the Transfer switch methods and configurations, which depends on how the Generator is configured.


HOWEVER not having access to Inverter diagrams and internal wiring schematics (and different types and brands may also ne different), I'm just unsure how they are configured. No problem with transfer from Utility to Inverter, you simply switch/transfer BOTH the Hot and Common or Neutral.


My "unknown" is if their output is in effect an "Isolation Transformer" (which I suspect) with 120 VAC Line to Line BUT NO NEUTRAL

OR if it even has a Neutral (which I doubt)

OR if it does and its a center tap on the output transformer (which I doubt) is it bonded to the case/frame, (which I also doubt)

OR if one leg (one end of the transformers output winding) is bonded to the case/frame (which I doubt)


OKAY CALL ME A DOUBTING THOMAS get the picture lol I suspect a straight 120 VAC Inverter output is an Isolation Transformer 120 VAC Line to Line HAVING NO NEUTRAL and no case/frame bond from any part of the transformer. I see no problem in bonding an Inverters case/frame to the RV frame which is also the DC Battery -.


Soooooooo does anyone have any hard evidence and schematic diagram of their particular Inverter to show how its output is configured????


If you take a continuity tester and attach one lead to the Inverters 3 prong receptacle, is there continuity from the Ground pole to Neutral??? is there continuity from Ground pole to case/frame????


NOTE if an Inverter were 120/240 (instead of a typical 120 only), then I suspect its the same as a utility transformer having a center tapped secondary


I have to go somewhere today but I plan to do that to my own 2000 W PSW Inverter when I can


Again even if one brand is configured one way, that don't mean another brand is grrrrrrrrrrrrrrrr I HATE NOT KNOWING its in my DNA lol In Law School when studying Trial methods the first thing they teach is when asking a witness a question NEVER ASK A QUESTION TO WHICH YOU DONT ALREADY KNOW THE ANSWER..........


Later gang, I'm headed out for the day, check back later.


An ever curious John T

Link to comment
Share on other sites

I read John's post a little differently. I read it as him pondering on smaller inverters, without the charge option. In this case, most manuals don't have any kind of technical info, and many suffer from a poor translation of Chinese to English. In 1 case, I have seen a schematic, but don't remember the brand. It did show a floating neutral, as John suspects. It had a 3 wire receptacle, with the bonding conductor tied to the inverter case, but neutral and line floating. I don't remember using a meter on it, so I can't confirm what the N to ground voltage was. I do remember that the instructions called for a bonding conductor of #10 AWG or large, to be connected between the vehicle frame and the inverter case.

I have been wrong before, I'll probably be wrong again. 

2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication
2006 smart fourtwo cdi cabriolet
2007 32.5' Fleetwood Quantum

Please e-mail us here.

Link to comment
Share on other sites



That Outback FX Manual was great I actually read much of it, the Xantrex link was only the first page. It looks like if you take the time to totally digest the NEC reference (I saved that, thanks) the answer lies within, and its the same difficulty I had interpreting the NEC way back when I was practicing, you cant read a line without having to go back to 2 or 3 references to understand it, and those also have 2 or 3 other back references and exceptions, it will drive you to drink. I thought briefing legal cases and researching statutes was hard in law school, that cant hold a handle to reading and interpreting the NEC lol I attended NEC Seminars by the likes of Joe McPartland and Mike Holt back in the day, now those guys were EXPERTS...............


YES I was thinking more about the smaller cheaper say 400 up to 1000 or 2000 watt Inverters when I posed the question




I think the more expensive Inverters may be wired and configured as what the NEC would consider a "Separately Derived Source" and may actually have a true Neutral which is bonded and I know and understand how to deal with and transfer such sources. HOWEVER I think the cheaper low end Inverters are similar to an isolation transformer output with 120 VAC Line to Line no Neutral and no bonding.




Sure I understand and might offer an opinion on supplying power to an Inverter, but not being 100% sure how its output is configured, I'm going to pass on any detailed wiring advice from now on. One thing regardless is to obviously use a 2 pole Transfer to switch utility Hot and Neutral to L1 & L2 of the Inverter regardless of all the other concerns, but Neutrals and Grounds I'm not gonna talk so much about unless its obvious and I understand it.


I feel better now, thanks for the responses. I think I better understand what it is I don't know now lol DO AS THE MANUFACTURER SAYS


John T Engineer and Attorney, one heck of a combination and curse causing excess concern over things like this grrrrrrrr

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

RVers Online University


RV Destinations

Find out more or sign up for Escapees RV'ers Bootcamp.

Advertise your product or service here.

The Rvers- Now Streaming

RVTravel.com Logo

  • Create New...