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Small Cabin Forum / Off-Grid Living / Still confused about Generator grounding/bonding.......
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Borrego
Member
# Posted: 1 Oct 2017 11:26
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Just got back from the desert and hooked up the generator to a power inlet box and the panel....Sure was nice having real light in the cabin after 8 years of flashlights and lanterns...! Generated a few questions, though...

I've been searching this forum and others to try and figure this out, but it seems as though there are varying opinions on this. Everyone has different generators, transfer switches, house panels, etc....Thought maybe I should lay out exactly what I have in terms of equipment......

I will be adding a solar system this year and I suppose that factors in also, but my main concern right now though is to have this safe to use now for the next few months, while i get the solar in and running....

1) Honda 3000 generator - neutral bonded to frame (correct?)
2) This is the power inlet - https://www.amazon.com/gp/product/B074JPYPW8/ref=oh_aui_detailpage_o02_s00?ie=UTF8&ps c=1
3) Picture of panel wiring:
Questions:
1) Do I need to have a separate buss bar for the grounds in my panel?
2) Do I need to separate the neutral from the frame of the generator?
3) I will put a ground rod near the panel, should I have one by the generator as well?

Thanks all!
IMG_20170930_0740043.jpg
IMG_20170930_0740043.jpg


toyota_mdt_tech
Member
# Posted: 1 Oct 2017 13:49
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Your Honda 3000 has no neutral. I think the generator chassis has a ground screw and they would want you to hook a ground to it would be my guess. Honda makes an EB2000i, it has a neutral and is bonded to the chassis. Looks the same as the EU2000i, but has a true neutral and chassis bonded. I see they make an EB3000, but it doesnt look quiet, looks like a noisy unit by appearance.

They will probably tell you to separate the neutrals and grounds at the panel (leave the white wires on it, add a separate bar for grounds and make sure bonding screw/strap at existing neutral buss is removed to insulate it from the panel chassis, and then run a ground rod near the generator and ground generator chassis. Run a copper wire from panel ground bar to ground rod and bond the generator to the ground rod also.

Page 76 of the owners manual
http://cdn.powerequipment.honda.com/pe/pdf/manuals/00X31ZT76221.pdf
shows "main winding" and that is the stator and there is a "WYE" point (middle common tie point is where neutral comes from), but no wire coming from it. That is where your neutral would come from.

I have mine set up like yours, wired like it was a primary panel, not a sub panel, feed it just like yours, bridged line A and line B at the panel to energize both sides (do this when feeding it with 110V) and its been working flawless for years.

Borrego
Member
# Posted: 1 Oct 2017 14:29
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Thank you, TMT! I figured you'd be responding

So just leave the panel wired as is then? It works fine, no issues there, just wanted to make sure I don't need to separate the Neut/Grnd...(It is like a main panel now, and not a sub panel (which I see no problems with)

I'm going to add a ground rod nearby (although with the rocks....I may have to get creative...)

toyota_mdt_tech
Member
# Posted: 2 Oct 2017 08:48
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I would say if you use the ground rod and bond the generator, I would separate the ground/neutral bond inside the panel. That would be pretty simple, go to Home Depot, buy another BUSS bar in the panel section, screw it to the inside (there is mounting points in there already for it) and run the grounds all to it, neutrals to existing bar, and remove bonding (usually a green screw or strap)

As for that ground rod, you dont have to go down, you can go sideways a bit too to avoid rocks.

Borrego
Member
# Posted: 2 Oct 2017 09:42
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Thanks!

Jebediah
Member
# Posted: 11 Jan 2019 10:22
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Why is it wrong to ground the panel and the generator...I see this mentioned all the time but no one has ever said what could happen if both are grounded....I'm no electrician and I'm curious...

Bancroft bound
Member
# Posted: 11 Jan 2019 10:35
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Neutals are grounded at 1 point only.
Usually in main switch, but at genny works too.

SCSJeff
Member
# Posted: 11 Jan 2019 11:07
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Just to clarify (for myself and maybe others)...

The Neutral should only be bonded to ground at 1 point.

Is it not OK, however, to actually ground both the panel and the generator to a grounding rod (either same rod, separate rods, or separate rods connected to each other (this is how I was planning on doing it))

ICC
Member
# Posted: 11 Jan 2019 14:25 - Edited by: ICC
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Quoting: SCSJeff
Is it not OK, however, to actually ground both the panel and the generator to a grounding rod (either same rod, separate rods, or separate rods connected to each other


Grounding is the most confusing part of electrical system design. Adding to the confusion is that local codes may vary, sometimes just because a new code that is different has come along but has not yet been adopted everywhere. Other times local earth conditions may call for different treatment.

NEC has provision for requiring 2 ground rods, spaced a minimum of 6 feet apart when the soil to conductor resistance exceeds 25 ohms. In reality, the two grounds should be 16 to 20 feet or more apart. Those two rods are to be connected to each other and then only one ground conductor from one of the rods connected to the system.

There should only be one ground conductor from the system to the ground rod(s). !!

Keep any ground rods that are connected to any lightning rods separate from the grounding system for the power system.

Introducing a generator into the system can complicate things as what needs to be done depends on how the generator ground neutrals are configured. Withtbeh grounding rods, if more than one, they should be connected to each other by a buried wire.

Mike 870
Member
# Posted: 11 Jan 2019 15:07
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Jebediah,

As I understand it, the reason for a single ground is that the neutral current can start taking the wrong pathway to ground or in the case of two neutral-ground bonds, the wrong pathway back to the neutral buss bar. Want to keep that current on the white wire and not end up with it traveling through things that were simply meant to be bonded and grounded.

toyota_mdt_tech
Member
# Posted: 11 Jan 2019 15:51 - Edited by: toyota_mdt_tech
Reply 


Quoting: Jebediah
Why is it wrong to ground the panel and the generator...I see this mentioned all the time but no one has ever said what could happen if both are grounded....I'm no electrician and I'm curious...


My guess is because there is no neutral or ground in a generator unless its a special type like the EB2000i for example. A neutral generator has a hot leg and a neutral, while a no neutral generator has 2 hot legs. Would you hook up a hot leg of your generator to the ground of generator chassis?

Now the WYE wound stator has a neutral in it electrically. But its not used like a home system is, in fact, its not used at all in a generator. Each side produces 60 volts peak from each leg, so peak to peak is 120VAC. OK, that is RMS voltage so peak to peak will be more. Peak voltage X 1.414

I am certain larger home standby generators use a line line neutral set up, ie a true neutral system. But us cabineers use our Honda EU2000i's etc

old243
Member
# Posted: 13 Jan 2019 08:57
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Regarding ground rods and rocky ground. You can purchase ground plates. They are a steel, galvanized square plate . With the attachment point to connect , ground wire to it. Dig a hole as deep as possible and place plate in. A place where water drips off an eve , keeps the ground moist for better grounding. Hope this helps. old243

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