Grounding Portable Generator

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Waterbear
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Grounding Portable Generator

Post by Waterbear »

Does a portable generator require grounding while charging thru shore power plug? If so is a Stanion Screw or
Backstay Mount OK?
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Wa2paa
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Re: Grounding Portable Generator

Post by Wa2paa »

:idea: While I am not a licensed electrician, only a licensed Ham Operator....with a Genuine Pure respect for professional advise when it comes to A/C Shorepower, GenSets, Modern Inverter Generator/Chargers... Used in a Mixed portable marine setting.

Please have a look, @ this web site.... IMHO: real good insight. :idea:
http://www.proboat-digital.com/proboat/ ... pg=59#pg59

Please be carefull:
Capt jack
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The Mutt
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Re: Grounding Portable Generator

Post by The Mutt »

They are portable for a reason, all the generators I have used have been fully self contained and designed to use almost anywhere, thousands of generators are already in use on yachts all around the world, ask a few owners at a marina what they have done.

Don't confuse the earth portion of an A/C circuit with grounding, it could be fatal.

The only time I have come across a generator that was earthed was on a motorhome, the owner wanted to minimise interference ceated by his antiquated generator that was disrupting his television reception.

Glenn
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Russ
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Re: Grounding Portable Generator

Post by Russ »

I'll let other with more knowledge chime in. But to "ground" means to tie it to the earth. Grounding to the mast doesn't seem to qualify. I guess some might ground to something in the water, but what if YOU are in the water?

"Grounding" at sea seems to be impossible. Now if you are tied to a shore power cord, you certainly can ground to the earth.


--Russ
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Nautek
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Re: Grounding Portable Generator

Post by Nautek »

The only surefire way to ground at sea is to put in an earth plate similar to that used for SSB radios
It is a bronze plate attached to the hull on the outside with a wire on the inside going to the generator

Allan
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Re: Grounding Portable Generator

Post by Waterbear »

Again I've use the wrong general term for a specific situation. On my mooring when I need to charge my Batterries
with a portable generator do I need to hook the "ground" from the generator to the boat. The generator ground is
a sperate bolt with nuts away from the 3 prong AC plug ins.
I have an 8ga 3 prong electrical cord with an adaptor to plug into my transom shore power plug. This will then power the converter to charge the batteries, as it would if connected to shore power.
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Nautek
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Re: Grounding Portable Generator

Post by Nautek »

Waterbear
No point in using the ground on the generator if the boat does not have a ground plate

Allan
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noahvale
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Re: Grounding Portable Generator

Post by noahvale »

I am an electrician with 37 years experience. If there is a ground point available, then yes you should ground the generator if you are going to use it in the marina. That would be the green grounding conductor. But why would you use your generator when you are connected to shore power?

If your electrical panel has a metal enclosure, that should be grounded when hooked up to any power source. All green grounding conductors from circuits on your boat should be connected to a grounding buss inside the panel that is connected to the enclosure.

If you are connected to shore power while using the generator, you should connect to the grounding conductor of the shore power system, which is case (B) below. That is the green conductor of the shore power connection. If the shore power is connected to the panel at the same time as the generator and both connectors have the GREEN (grounding) conductor connected to the metal enclousure/case ground of the panel, that is all that is necessary. Note that the WHITE neutral (grounded) buss should not be tied to the the green in the panel.

This is what the latest National Electric Code says about grounding generators:
702.10 Portable Generator Grounding.
(A) Separately Derived System. Where a portable optional
standby source is used as a separately derived system,
it shall be grounded to a grounding electrode in accordance
with 250.30.
(B) Nonseparately Derived System. Where a portable optional
standby source is used as a nonseparately derived
system, the equipment grounding conductor shall be
bonded to the system grounding electrode.
Without a metal hull, or something metal in the water to use as a Grounding Electrode, there is no way to connect to one. If your panel is wired correctly, and the connection from the generator to the panel has the green grounding conductor connected, it will be safe enough in a closed system like a boat when at sea.
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School House Steve
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Re: Grounding Portable Generator

Post by School House Steve »

Uh, I don't think grounding would be a problem as long as you keep the generator away from shallow areas of water. :)
Kelly Hanson East
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Re: Grounding Portable Generator

Post by Kelly Hanson East »

:D :D
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Re: Grounding Portable Generator

Post by Hardcrab »

If I read your post correctly, you want to charge your batteries from a charging unit plugged into a generator.
Boiling that down, I assume what you are asking is, in effect, will the "case grounds" need to be addressed?
By case grounds, I mean all metal enclosures for the various items associated with power will have their exposed metal pieces electrically connected to each other to preclude a very specific shock hazard.

My take will be that IF your charger has the third prong on it's plug, AND the generator has a third prong receptical, then "case grounding" been done with the third prong and the problem is addressed.
(If no third prong, it's prolly a plastic case and therefore no case grounding is required or possible).

"Grounding" to the mast or stanchions will have zero effect.

You could run the ground wire from the generator case to the ground connection in the shore power plug or panel, etc., but for no real good reason, assuming the generator will not be used while on shore power.

Charger unplugged from shore power to plug into generator while on the hook, third prong on everything, good to go.

I suppose this is what Noahvale has already posted, sorry for the repeat.
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