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Small Cabin Forum / Off-Grid Living / Need help on Bonding/ Grounding Panel
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Alaskan
Member
# Posted: 15 Apr 2019 07:01
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Hello--Been reading a lot of discussions on generators/ floating neutral/ grounding etc. Now I am completely confused! Need some input.

I have wired a small cabin and am powering it with a Honda EU200i. I wired it like a house and put plugs on the end of my circuits which I have been plugging into a power strip energized by an extension cord from the generator. I am now trying to make things more permanent and am installing a main breaker panel and need some help on wiring the panel.

I bought a Eaton BR 125 Amp 8-Space 16-Circuit Indoor Main Lug panel. I have run some 10-3 UF-B wire from the generator shed to my panel and plan to use an AC WORKS [AD515L1430] Household Plug NEMA 5-15P to Generator 4 Prong L14-30R (Two hots bridged) that I'll plug into my generator.
I'm told I could have just had a jumper on the two hot busses in the panel but too late now.

At the panel I plan to wire the black and red to the Hot buss and the neutral to neutral bar, and ground wire connected to earth to ground bar.

I just recently learned that this generator has a floating ground--and though I can't say I fully understand this, I'm wondering if I need to bond the neutral and ground in the panel somehow. An electrician told me that I need to ground the genny, but I'm reading from others that that is not advisable. So... with a floating neutral--do I need to bond the neutral and ground at the breaker panel? DO I need to do anything at the genny--like bond the neutral and ground with a made up plug doing just that? Any input would be appreciated.--- and thanks for all of the intel located on this site!

creeky
Member
# Posted: 15 Apr 2019 08:58
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This is a good clear overview.

I still struggle with bonding/grounding. With a floating neutral (as I understand it): once you plug in its grounded. I'm assuming of course that you have your main panel grounded to an earth bar/plate.

ICC
Member
# Posted: 15 Apr 2019 10:05 - Edited by: ICC
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You should have a ground rod at the cabin connected to the ground lugs in the service panel. That should be the only connection to a ground rod. Note, that for the best ground connection that one ground wire should actually connect to two rods in the ground that are spaced 10-12 feet apart but connected with a single wire that goes to the first rod and then unbroken to the second. Only one wire from the panel ground connection.

Then, as for the neutral-ground bond, yes the Honda 2000i has a floating neutral, or in other words, an UN-bonded neutral-ground. Make the nuetral-ground at the panel and simply plug a standard cord between the Honda and the panel entrance plug.

That trick with a made up plug which bonds or connects the neutral to the ground is usually only needed for some special things like feeding power into an RV that has equipment that needs to "see" that bond. (Some newer HE RV furnaces for example) from a portable generator that has a floating neutral. FWIW, I think the term floating neutral causes confusion. Should just be called un-bonded. To me that is easier to understand.

Not all generators have a floating neutral. That varies a lot. The Honda EU2000i does as do the comparable Yamaha.

However, if there is any chance that you or someone else might power the cabin with some other generator such as a typical contractor generator that has its own internal neutral-ground bond then there will be two bonds and that is not correct. So, in that case, using a "cheater" plug at the Honda to provide the neutral-ground connection when connected to the cabin makes some sense.

toyota_mdt_tech
Member
# Posted: 15 Apr 2019 10:20 - Edited by: toyota_mdt_tech
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The genny frame, ie metal chassis can be grounded. But electrically, its insulated from generator.

There are some generators that actually have an actual neutral wire. You have to look at the stator disgram, a neutral comes from the tie point in a WYE wound stator. Most just have a series of could over a pair or 2 pairs of poles (depends if its a 2 pole or a 4 pole genny) but no wire comes from it, this is the case with a inverter generator, its a 3 phase AC fend into inverter, thats the last you see of the 3 phases, the inverter makes it single phase AC electronically.

Most generators have half of the output on one side (peak voltage) while the other half comes from the other leg (peak voltage) which means you may have 80VAC on each leg for a total peak to peak voltage of of 160VAC or a true RMS voltage of about 113VAC (about 70.7% of peak to peak voltage)

So I would think bonding neutral and ground together would charge your ground when you bond gennie chassis to ground.

In your main panel, I would keep them separate (removing green bonding screw or bonding strap, but keep it handy) and if you running off grid and a gennie, keep them insulated. But if you ever hook to the grid, the primary panel, neutral is required to be bonded to a grounding rod. All subpanels are not bonded.

In generator language, you have to drop the idea of line (hot) and neutral, just think of both as hot. Floating means not bonded. Like a floating ground. If you grounded your gennie on its own ground rod, it would be floating. A Honda EU's are all plastic, but do have a grounding lug.

There is an OSHA version of the Honda generators. Its the EB2200i, it will come GFCI protected, has a true neutral and its bonded to the frame.

https://powerequipment.honda.com/generators/models/eb2200i

It has a neutral and its bonded to the frame and ground lug. This gennie, I would keep panel bonded? Not sure, since its bonded at the generator already.

The EU220i has a floating ground, not bonded to anything unless you hook up a ground rod, so 3rd pin of outlet is dead anyway. Not electrically tied into the generator at all.

ICC
Member
# Posted: 15 Apr 2019 10:21
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An article as to how this applies to RV use. Maybe a help to understanding?

https://www.rvtravel.com/how-generator-neutral-ground-bonding-for-an-rv-works/

Alaskan
Member
# Posted: 16 Apr 2019 03:57
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Thanks for all of the input and responses. Can't say I'm grasping all of it unfortunately. I'm thinking I need to be more clear in what I'm actually doing at the cabin though. For starters, this cabin will never be hooked up to another power source as it is remote---so it's only ever going to be powered by a generator. I ran the 10-3 wire from the generator shed to my panel. At the generator I wired the 10-3 to a 4 pronged plug and then will plug that into a 3 prong that bridges the 2 hots and then that will plug into my generator
(See https://www.amazon.com/gp/product/B00002NATY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF 8&psc=1

and
https://www.amazon.com/gp/product/B074PWJVWC/ref=ppx_yo_dt_b_search_asin_image?ie=UTF 8&psc=1 )

I thenran the 10-3 to my panel--the only panel and I put one hot to one post and the other hot to the other post, neutral to neutral bar and a bare copper ground to a ground bar on the panel. I ran this un-insulated wire to a metal helical post that is driven down about 25 feet to bedrock which is one of 6 that my cabin sits on. (see tmp Alaska). (One question I have as I write this is that the ground is bare and goes through my sub floor and insulation---does it need to be insulated or separated from the wood etc?)

I'd like to take the suitcase generator back and forth from the cabin. If it is safe to not ground it (it is grounded internally) then I'd like to just keep it that way. Several have also stated there should only be one ground--which should be the panel--so won't that suffice?

ICC, you wrote "Make the nuetral-ground at the panel and simply plug a standard cord between the Honda and the panel entrance plug.--but I'm wiring the wiring directly to the panel and then putting a plug on the other generator end. Is there a reason not to do that? Wiring the panel plug is my question I guess.

So finally--if I run the wire as mentioned above, can I just have ground go to panel and ground bar, white go to neutral bar, and 2 hots to 2 hot lugs WITHOUT bonding the ground to neutral? My apologies for the confusion and lack of understanding on my part.--Appreciate the help and input

toyota_mdt_tech
Member
# Posted: 16 Apr 2019 08:26
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Alaskan, that is exactly how I run my generator into the cabin, never an issue. I did not tie the ground to my generators neutral. (which really isnt a neutral more than likely) so in your case, if it was me, I would use your ground rod as you have set up to the ground bar, then your line, line and neutral. Remove bond screw in panel? If its a true neutral, then leave bond screw/strap in like you have.

You didnt mention if the generator was a 110V or A 220V unit?
You mentioned 2 hots, so I assume its a 220V generator.

Either way, it will work just the way you have it. Bare copper wire through floor to rod is fine too. I would say you are set and ready to roll.

Alaskan
Member
# Posted: 16 Apr 2019 08:54
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Toyota_mdt_Tech, thanks for the reply. It's a 110V Honda eu2000i generator with the floating neutral. The two hots I am wiring to the panel lugs are created by the 4 pronged locking female adapter to 3 pronged with the hots bridged within the plug (link above). Am I still good? Thanks Toyota Tech!

toyota_mdt_tech
Member
# Posted: 16 Apr 2019 15:42 - Edited by: toyota_mdt_tech
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OK, if its a 110V only generator, the black leg (we will think typical AC home wiring) will hook to the one lug where line would normally come in, white, hook to neutral bar, remove bonding screw, run a separate ground bar, run that to your ground rod.

The jumper inside the cord will work, as long as its only used at your cabin. An easier way is, build the cord normally, no internal jumper then do this:

Now one more item you will need to do to power up all legs in breaker box is to jump the input line lugs together. Run a jumper from the one lug with the black wire, run it over to the other side. Now when you wire a circuit, black wire to breaker, white wire to neutral bar, bare or green to ground buss. Just make sure jumper is same size as your other wire, ie 10AWG.

Jebediah
Member
# Posted: 16 Apr 2019 16:28 - Edited by: Jebediah
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I think I seen one hook up where the guy just ran his genny /exstension cord to a 240 breaker in the panel to power all legs of the panel/no need for jumper wires...

toyota_mdt_tech
Member
# Posted: 16 Apr 2019 18:00
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He only has a 110VAC unit, but that would certainly work with a 240, it would consume 2 spaces, so if you have a small panel to begin with...

Alaskan
Member
# Posted: 16 Apr 2019 19:34
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I’m running a 10-3 wire from the generator so red and black will go directly to hot posts making both sides of the breaker panel hot. The jumper then is in the plug that is plugged into the Edison outlet at the generator. Does that make sense?

Jebediah
Member
# Posted: 17 Apr 2019 06:37
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I think the guy was using the 240 breaker like a back feed as he was on grid power, which I've been told isn't recommended....
Quoting: Alaskan
I’m running a 10-3 wire from the generator

I believe your set up is Identical to mine...

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