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Pictures posted for farmANhvacguy:







I'll get hvacguy to explain what is going on here.

This is a outlet I pulled out of a 28KW winco PTO generator It had no neutral wire just this jumper connecting the neutral to the ground. Seems to me once the plate screw on that outlet got loose it would get a little sparky...........

That what the older generators were used to do that but with current codes etc it no longer legit due the safety issue like what you ran into it.

and in 2011 NEC code cycle everything on generator it will have to be GFCI on 120 volt circuit not sure about 240 volt circuit they may include it or not.

Merci,
Marc

GFI? Doesn't that require a ground reference? All small portable generators here are floating systems without a grounded pole, so all they can do is use protection like in an IT (isolated ground) system.

No, Texas, a GFCI does not need a 'ground reference.' All a GFCI does is measure current going out through the hot wire, and compare it to current coming back in through the neutral wire; if they don't match, it trips.

If the generator isn't grounded somewhere the GFCI will not trip because there is no return path to unbalance the circuit.
I know we always say you don't need a ground to trip a GFCI but that is because the utility is a grounded supply.

I can understand that view; but by the same token, there cannot be any current flow without a return path of some sort back to the source. It matters not if the source is the PoCo or the generator.

No current flow = no shock hazard. As soon as there is current flow, the GFCI will trip- unless all of the current is returning via the neutral wire.

Naturally, no GFCI, on any system, will help you if you are the path between the hot and the neutral wires.

Pardon me if I don't see the issue here.

Are not neutral and ground normally strapped together at the distribution panel?

Since the genset is the power source, distribution panel and outlets all in one, wouldn't it make sense to strap them together there?

Or should they be strapped together before the run to the outlet?

Since the frame of the generator MIGHT be grounded, I would want a nice solid return path in the event that hot shorts to a metal chassis in a tool that I'm using. Better to trip the breaker than have 120V AC finding a convoluted path through my body, into the ground and back to the genset...

Correct my amateur self if I'm wrong.

We have to separate a generator out in the yard that is not connected to anything but the loads from a generator that is connected to the home wiring, no matter how.

If this is just an unconnected generator, like Reno says, there is no fault path and no shock hazard

I have a Honda EU2000. Neutral is NOT connected to ground. Case is plastic. Although you could have an internal fault that would cause a ground fault (on ether leg)I like using this unit to power tools and such used in wet or damp locations due to its isolation. I have to admit, this unit is one of the best purchases I have made. Quiet, only 49LB, 12-14 hrs on a tank of gas,very stable voltage and 60 cycle ( 1.1 gal)Beats a 200 ft extension cord.

I completely agree, there is no problem here, in fact the neutral MUST be strapped to ground per code, and this is as good a place as any for the manufacturer to do so. Big commercial generators do the exact same thing, just with a larger wire.

Of course, modern generators of this sort should be GFCI protected. The GFCI would work just fine even without any solid bonding to ground. If the generator is insulated and there is a ground fault somewhere, no current flows because the "hot" wire is now the only grounded point in the system, and the ground/neutral are now rotating 120V above ground. Of course, it's highly unlikely that the hot will be grounded and ground not intentionally or incidentally grounded at some point. This is why the ground/neutral bond must be made on the line side of the GFCI circuit. If it's a very weak incidental ground, like the grounded gen rails are sitting on a concrete slab, you still might not get the 5ma required to trip the GFCI, but then, if you're not getting 5ma, then it's not really an issue, is it?

It is like an IT system - one ground fault and you're fine because you just grounded one leg of the generator like in house wiring. If you get two ground faults then things get nasty.

So then its ok for 20 amps to flow from neutral thru tab into ground screw into outlet body.........the ONLY connecting to the commen ground/neutral on this generator is the plate screw into the frame... Doesnt seem right to me

I think you have the flow backwards.

There's a neutral wire back to where the generator makes the electricity; what's lacking is the ground wire. So, only current that has energized the frame will use that tab, to return to the system.

no reno this is my picture there was NO neutral wire..the tab was the "neutral wire"


On the new outlet I ran a wire from the commen ground/neutral block and ran a green wire from the outlet to the generator frame.

this seems a little bit safer to me

OK, if that's the case, I stand corrected ... and I don't like the design either.

So, there was only a hot connection, and neutral/ground through the generator frame?

do we have a generator model, i want to go look up a wiring diagram...

I am pretty sure the OP mention to me some time back it is a WINCO pto generator I don't recall what KW size it is but I am pretty sure it is 15 KW size but I will let the OP give the correct infomation here.

Merci,Marc

No need for a ground to trip a GFI, as it simply measures the current going thru the hot, and compares to neutral. If they're not the same, GFI trips, aggravates user. XD