Bonded or Floating Neutral for generator?

[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.