Inverter for RV hookup. Manufacturers reply.

[lawrosa]

Hi all. So I read contless online info about the whole bonding issue with Rv,s.

I understand the RV is basically a sub panel. The bond is made when you hook up to the pedestal. OK.

with a generator I guess who you talk to you can run both ways. Bonded gen or no bonded gen.. I have a kohler 2800 bonded gen with GFI.

OK now to my inverter that I will hook up in the camper. I will be plugging the RV umbilical cord into the inverter. ( I will turn off charging circuit at converter)

The inverter will be a krieger 1100 model. I already bought it as it has a 3 yr warranty. Upon a test of the invertor with my test plug inverter show open neutral/ground. ( Meaning its not bonded)

I did a test and got continuity from the ground plug to the grounding terminal on the case of inverter.


So I was not sure to make a plug or not to bond the G/N at the inverter. Or leave it as a floating neutral for when I plug in.

Here is my question and response from krieger.

Do you guys know what this means?

Does it mean I should disconnect the ground wire in the dog bone connector I make and just use the hot/neutral wires when connecting to the inverter?

If so can any electricians out there tell me why to do this?

I dont think customer support guy understood what I was doing and he may be wrong...

Question and reply to krieger..

HI,

Possibly you can help me with a technical question.

I have a Krieger 1100 watt inverter. I will be installing this in my rv travel trailer.

The travel trailer is basically a sub panel. So when I plug into the camp grounds pedestal I get the bond at the service entrance.

This would also stand true I assume for my 2800 watt gas generator. When I plug the RV to that I get the bond from the generator. This generator is bonded neutral/ground.

I notice your invertor has an open neutral from my test light. I will
be running a ground wire from the back of the unit to the trailers frame.

What I am going to do is essentially plug the RV into this invertor to power it. This will power all my outlets in the trailer. I will be turning off the charging circuit so there is no endless loop going on.

I am not sure if I should bond the N/G in the krieger invertor. I would plug a n/g plug into the extra outlet to accomplish this.

1. Should I leave this as an open neutral unit or make N/G plug to
bond the neutral and ground? ( Attached is an image of said plug) 2.
What gauge wire should run from grounding terminal in back of unit to
frame of trailer? ( I was going to use 6 gauge)

I hope you understand this and can help me.


Thanks

Mike NJ



HI Mike,

Thank you for the provided information about your application. We recommend using only the hot and neutral on the plug only and do not use the AC ground when connecting the inverter to a breaker panel box. You should use #10 gauge cable when connecting the ground chassis located on the back of the inverter to the frame of the trailer.


Customer Support
Krieger Manufacturing
2933 W. Cypress Creek Road, STE 202
Fort Lauderdale, FL 33309
Tel: 1.954.603.4950


Ok just to be clear in laymans terms,

So you recommend just plugging the RV into the krieger inverters outlet, with no modification to the neutral/ground, even though it will show as open?

Yes I will use 10 gauge or better for the chassis ground.

Also would you be able to supply a schematic for this 1100 watt inverter?

Thank you for your time. Its much appreciated......

Regards

Mike NJ


The modified wave inverter shows an open or floating ground compared to power received from your AC wall outlets. This results in a incompatibility when connecting to a breaker panel box. The best way is to just use the hot and neutral legs on the inverter's AC outlet and do not use the ground connection when connecting to a breaker panel. We still recommend grounding the inverter by connecting the 10 AWG cable to the ground chassis terminal located on the back of the inverter. You can consult with a qualified electrician for proper installation if needed. We do not provide diagrams, schematics, or a parts list to any of our products due to proprietary reasons.


Customer Support
Krieger Manufacturing
2933 W. Cypress Creek Road, STE 202
Fort Lauderdale, FL 33309
Tel: 1.954.603.4950

[MEXICOWANDERER]

Pretending To Camp In The Driveway...

Kudos. That's the smart way IMHO. Iron out the wrinkles without consuming precious vacation time.

Monitor your batteries so you know beforehand just how much you can get away with.

[lawrosa]

heres the final reply I got from the maufacturer.. I went ahead and connected the ground wire...

Yes, we are referring to the residential breaker box. However, since your RV's breaker panel box neutral and ground are not bonded together, you can plug the breaker panel box directly to the AC outlet on the inverter (as already setup and shown in your picture). Your setup appears good.


Customer Support
Krieger Manufacturing

cs@kriegermfg.com



-----Original Message-----
Sent: Saturday, June 3, 2017 9:56 PM
To: cs@kriegermfg.com
Subject: Re: Neutral ground bond



Hi customer support...


OK I got my inverter in and I just want to verify your statement about lifting the ground wire.

I know you stated incompatibility when connecting to a breaker box, but are you referring to a residential breaker box that has the ground/neutral bonded?

Just for reference I am plugging my RV into your inverter. RV breaker box's are not bonded. The grounds and neutrals are separate in any and all travel trailers.

With this new info does lifting the ground wire still apply?

Just a note:

The inverter works both ways. With the ground lifted and without the ground lifted.

I attached a pic of my set up. The ext cord I have plugged into the inverter goes through the floor and I installed a travel trailer 30 amp outlet under the trailer to plug in my travel trailer. In this plug is where I can lift the ground or not lift the ground.

I just want to be safe and make sure im doing the right thing with the ground wire..

Thanks for you help,

Mike L NJ.

[lawrosa]

MrWizard wrote:
open the back cover and unplug it, there is an outlet right there, the fridge is plugged into

Holy ***** !!! Your a genius.. I cant believe I didn't think of that... duh... I feel like an idiot...

You are indeed a wizard ....

[MrWizard]

open the back cover and unplug it, there is an outlet right there, the fridge is plugged into

[lawrosa]

time2roll wrote:

lawrosa wrote:
The only issue I have is the fridge is automatic 120v/LP gas.

No button to designate propane only? My Dometic does right next to the on/off button.

Nope one button on or off. It decides what it wants.

[time2roll]

lawrosa wrote:
The only issue I have is the fridge is automatic 120v/LP gas.

No button to designate propane only? My Dometic does right next to the on/off button.

[lawrosa]

Well took me a few days.. This the best I got for now.. With my one residential panel 40 volts I pump in 20 amps to the batts with this chinese charge controller... It works for me...

Im going to try out the inverter more this weekend. Basically pretend im camping in the drive way..

The charge circuit on my converter is on its own line with it a good thing..

The only issue I have is the refridge it automatic 120v/LP gas.

So if I plug the inverter to the camper the fridge will want to run off 120v..

So I need to flip the refridge breaker. Problem is the 3 outlets in the master bedroom are on the refridge breaker. Not on the breaker itself but somewhere..

How do I find this? Ill pull the cover off the converter and see what I find in a couple days... I may just have to live with the fact that when boon docking I will not have use of those 3 outlets..

[BFL13]

Don't know. The inverter I noticed all this with was the CanTire PSW 1000w job. Only found out because I was poking around--no need for that with most RVers :).

Using it, didn't matter what you did. I only found out about it because it by-passed the neg wire battery disconnect I had at the time, when I plugged in the shore cord to the inverter.

Otherwise, you would never know and wouldn't care.

[brulaz]

BFL13 wrote:

...
Another inverter I was using had GFCI receptacles and chassis ground. When the shore power cord was plugged into the inverter it somehow found a neg path to the DC fuse panel. The shore cord is grounded to the frame at the Power Centre and so is the 12v side of things, so 120 and 12 share the frame as negative/ground. The inverter's chassis ground joined in with that
...

Sounds like my Kisae with GFCI sockets.

The Kisae 120VAC Neutral at the socket is wired to the case.
The case is wired to the chassis.
The chassis is wired to the trailer's 120VAC ground wire.

So when the shore power cord is plugged into the Kisae socket, neutral and ground are bonded. And my EMS loves it.

But if I just plug an appliance into the Kisae, not using the shore power cord and bypassing the trailer's 120VAC circuit, neutral and ground are NOT bonded. Ground just floats.

My old 1000W inverter did not wire neutral to the case, or to ground, and so was unbonded all the time.

You would think there would be some applicable standard for this. Aren't inverters CSA approved (and/or US equiv)?

[MrWizard]

Notice
The wiring is not mentioned
Your RV breaker box is not bonded, so essenialy is one giant multi outlet extension cord, do not cut the ground wire, you do not need to cut it

Do NOT use bonding plug , those are for things like Honda generators, when the RV surge suppressor gives an alert of open ground

A bonding plug will probably let the smoke out of your inverter

[lawrosa]

road-runner wrote:
With respect to the AC output, there are two types of MSW inverters. One type has a true floating output and can be bonded if you wish. Higher end MSW inverters tend to be of this type. The other type of output, common in lower-end MSW inverters, was described in DrewE's earlier post. Both output conductors are hot with respect to chassis ground. What happens when you bond either output depends on whether the inverter has output short circuit protection or not. If it has short circuit protection it simply will stop working. If it doesn't have the protection, it will instantly go up in smoke. Verified (accidentally) by personal experience.

This is what it says... But I will test voltages tomorrow... I read that I will need a true RMS meter to read propervoltages...
How This Modified Sine Wave Power Inverter Works
There are two stages in which this power inverter changes the 12 volt
DC (or battery) power into 110v AC (household current).
STAGE 1: This inverter uses a DC to DC converter to increase the DC
input voltage from the battery to 145 volts DC.
STAGE 2: The inverter then converts the high voltage DC into 110v AC
(household current), using advanced MOSFET transistor in a full bridge
configuration. This design provides this Kriëger® inverter with the
capability to start and run difficult reactive loads, while providing
excellent overload capability. The waveform that is generated by this
conversion is a "modified sine wave" as shown in the diagram below.

[road-runner]

With respect to the AC output, there are two types of MSW inverters. One type has a true floating output and can be bonded if you wish. Higher end MSW inverters tend to be of this type. The other type of output, common in lower-end MSW inverters, was described in DrewE's earlier post. Both output conductors are hot with respect to chassis ground. What happens when you bond either output depends on whether the inverter has output short circuit protection or not. If it has short circuit protection it simply will stop working. If it doesn't have the protection, it will instantly go up in smoke. Verified (accidentally) by personal experience.

[lawrosa]

MrWizard wrote:
My take on this
assumming you are talking about an inverter that has power pass thru to be used with shore or generator power
Ground the inverter case to frame ground
Do Not mess with the internal wiring

A bonding plug is only needed when you have some device that gives you an alert, and won't function

No pass through or nothing like that... I guess I plan on just plugging it in as designed.. I would feel funny removing the ground wire on the cord im going to make up..

I wonder what the implications will be though since customer support states otherwise...

[MrWizard]

My take on this
assumming you are talking about an inverter that has power pass thru to be used with shore or generator power
Ground the inverter case to frame ground
Do Not mess with the internal wiring

A bonding plug is only needed when you have some device that gives you an alert, and won't function