Bonded or Floating Neutral for generator?

[stumblinhorse]

Ugggggggh, a suicide cord i`m guessing.
Ya know, its not as hard as you think, to do it the right way.

No suicide cord! Tryin my best to do it the “right way” but everyone‘s way seems to be different.

You plug a generator in to a 14l-30p mounted to your house. That goes to a transfer switch. That can be a simple lockout/breaker. That 14l-30p is attached to 4 wires, 2 hot that go to a double 30 amp breaker. Then the neutral and the ground attach to the bus in the panel. Those are attached to the ground for the structure. There is no need for a grounding rod on your generator separately. And the neutral for the generator needs to float. At least that would be my understanding.

In a portable situation the bonded neutral allows use of a generator without a grounding rod also.

My inverter does not have anywhere to even attach a ground rod…

 

[Jstpssng]

Pretty much no such thing here as a local electrician, local anything really. I do everything myself or wait weeks or months to get a call back. Doesn’t matter what it is, plumping, heating, electrical. I am doing the work myself.

We must be neighbors.

 

[buckeyefarmer]

No suicide cord! Tryin my best to do it the “right way” but everyone‘s way seems to be different.

You plug a generator in to a 14l-30p mounted to your house. That goes to a transfer switch. That can be a simple lockout/breaker. That 14l-30p is attached to 4 wires, 2 hot that go to a double 30 amp breaker. Then the neutral and the ground attach to the bus in the panel. Those are attached to the ground for the structure. There is no need for a grounding rod on your generator separately. And the neutral for the generator needs to float. At least that would be my understanding.

In a portable situation the bonded neutral allows use of a generator without a grounding rod also.

My inverter does not have anywhere to even attach a ground rod…

In this scenario I would float at the generator, since the bond is in a panel.

 

[npalen]

I found that my new Lennox furnace would not run when connected directly to the inverter. Had to make a dummy plug with ground and neutral connected and plug that into the inverter also.

 

[cqaigy2]

Ok, if using a generator at your place, so not power from power company. Why bond neutral to ground and put grounding rods in, whether you use the house wiring or extension cords? Now hear me out. I'm not an electrician. If the generator neutral is bonded to ground, and you drive a ground stake in for the generator, isn't that making it more dangerous? If you happen to grab a conductor that now has a voltage potential to earth ground, it would want to use us as a conductor right? If there was no ground rods, wouldn't there be probably no potential voltage difference to earth ground?

 

[stumblinhorse]

Ok, if using a generator at your place, so not power from power company. Why bond neutral to ground and put grounding rods in, whether you use the house wiring or extension cords? Now hear me out. I'm not an electrician. If the generator neutral is bonded to ground, and you drive a ground stake in for the generator, isn't that making it more dangerous? If you happen to grab a conductor that now has a voltage potential to earth ground, it would want to use us as a conductor right? If there was no ground rods, wouldn't there be probably no potential voltage difference to earth ground?

I think I agree with you that if you are using a generator to power a structure the safest way is to allow the structure to provide ground and neutral. If you have a bonded neutral and grounding rod on your gen, a GFCI gen will actually trip once enough load is on line.

But I don’t know what the fancy $300 transfer switches do to provide a benefit? They switch neutral and ground to the generator which to me is not as safe as using the structure? But same as you I am not an electrician.

 

[cqaigy2]

I think I agree with you that if you are using a generator to power a structure the safest way is to allow the structure to provide ground and neutral. If you have a bonded neutral and grounding rod on your gen, a GFCI gen will actually trip once enough load is on line.

But I don’t know what the fancy $300 transfer switches do to provide a benefit? They switch neutral and ground to the generator which to me is not as safe as using the structure? But same as you I am not an electrician.

Oh ya forgot about the GFCI.

 

[newbury]

This discussion combined with lack of accurate documentation is a safety headache.
All I want to do is SAFELY hook up my generator (Duromax 9000iH with bonded neutral) either to:
(1) Equipment directly - like plugging in an electric drill, or Extension cords to distribute to frig, window a/c
(2) To a proper connection and transfer switch to a subpanel to power my "critical" house circuits - a/c, microwave, etc.

But from my reading this thread it seems like (1) needs a bonded neutral and (2) needs a floating neutral.

What's the safest and easiest way to switch between?
Is a neutral-ground plug a valid solution?
neutral-ground plug

 

[stumblinhorse]

This discussion combined with lack of accurate documentation is a safety headache.
All I want to do is SAFELY hook up my generator (Duromax 9000iH with bonded neutral) either to:
(1) Equipment directly - like plugging in an electric drill, or Extension cords to distribute to frig, window a/c
(2) To a proper connection and transfer switch to a subpanel to power my "critical" house circuits - a/c, microwave, etc.

But from my reading this thread it seems like (1) needs a bonded neutral and (2) needs a floating neutral.

What's the safest and easiest way to switch between?
Is a neutral-ground plug a valid solution?
neutral-ground plug

I am sure you saw this?

 

[PILOON]

I think it is rather simple.
If the 220 VAC generator has a 3 prong connector there is no ground.
If 4 prong connector one has to be a ground with the others being hot/hot and neutral.

 

[hiddentacocatneddih]

Brown to brown. Orange to orange. Yellow to yellow. Green to green

 

[stumblinhorse]

I think it is rather simple.
If the 220 VAC generator has a 3 prong connector there is no ground.
If 4 prong connector one has to be a ground with the others being hot/hot and neutral.

I don’t think there is confusion on that

But nowadays all portable generators have bonded neutral. So in the situation of “4 prong” connectors, plugging that in will blow your GFCI breakers because of 2 paths to ground…

 

[CE2]

But nowadays all portable generators have bonded neutral. So in the situation of “4 prong” connectors, plugging that in will blow your GFCI breakers because of 2 paths to ground…

No ,it will not. A GFCI receptacle or breaker will “sense” the difference in the amount of electricity flowing into the circuit to that flowing out. so if there is current flowing somewhere else besides between the ungrounded conductor(hot) and the grounded conductor( neutral) the GFCI will trip. Currents in an amount as small as 4 or 5 milliamps will trip it. It does not mater if the grounded conductor is or is not connected to ground.

 

[stumblinhorse]

No ,it will not. A GFCI receptacle or breaker will “sense” the difference in the amount of electricity flowing into the circuit to that flowing out. so if there is current flowing somewhere else besides between the ungrounded conductor(hot) and the grounded conductor( neutral) the GFCI will trip. Currents in an amount as small as 4 or 5 milliamps will trip it. It does not mater if the grounded conductor is or is not connected to ground.

I guess you will have to explain that better for me to understand. You’re saying that plugging into a generator with a bonded neutral and ground into a panel that also has a bonded neutral and ground won’t blow the GFCI breaker? Because what I was trying to say is simply that it will trip the GFCI breaker.

 

[npalen]

The problem with understanding the subject matter of this thread is that posts really need to include some sketches, diagrams, pictures etc of what is being said.

This video seems to bring these to the table.

 

[cqaigy2]

I guess you will have to explain that better for me to understand. You’re saying that plugging into a generator with a bonded neutral and ground into a panel that also has a bonded neutral and ground won’t blow the GFCI breaker? Because what I was trying to say is simply that it will trip the GFCI breaker.

That's what i got out of his explanation. Won't trip.

 

[cqaigy2]

The problem with understanding the subject matter of this thread is that posts really need to include some sketches, diagrams, pictures etc of what is being said.

This video seems to bring these to the table.

That one made a lot of sense.

So when would you want a switched neutral?

 

[Hoss710]

I have always had my military generators tied to the same grounding rod as the power boxes when back feeding the house. They also say you can run a separate copper rod just for the gen. but I have always shared the same as the building.the neutral I have also back fed through the cable to the panel. the difference between neutral and ground is neutral carriers current. Ground is a reference.

 

[MAX-24-Dean]

That one made a lot of sense.

So when would you want a switched neutral?

Switching the neutral or not switching the neutral is just one of two ways that you are allowed to complete and generator installation, it a design choice.
Both ways are code compliant.
A transfer switch is less costly if you don't add the extra pole to switch the neutral.

So when would you want a switched neutral?
On an Industrial Electrical Service with ground fault detection/protection devices. The design requires the generator to be a seperately derived system. Switching the neutral off of the utility service and onto the generator makes it a seperately derived system.
At Healthcare Facilities with required Life safety systems and required emergency power systems.

The basic reason is if there is a phase to neutral short coming into the service from the utility you prevent possible damage to electrical systems by switching the neutral.
Phase to neutral shorts have happened during severe weather that damages the utlities distribution system.
I have seen the damage of a 6000 amp service blown off it's foundation because of a phase to neutral fault. so switching the neutral is a design consideration engineers usually make on large electrical services.

 

[CE2]

Here is a drawing of how to connect a generator. Note the neutral is not bonded to the ground wire at the generator. The ground is bonded to the neutral at the meter socket(the preferred method) or a the main electrical panel.