Properly installed portable generator inlet?

[electrofelon]

just a question out of curiosity....is there any risk, or possibly to receive a shock from a ground fault from a floating neutral genset since there’s no path back to the source?

example... metal power tool with phase conductor broke loose touching exposed frame. Since there’s not EGC and neutral bond and it’s not physically grounded.Any possibly way to still shock?

IMO floating generators are safer. Unfortunately here in the states we are so obsessed with grounding hardly anyone can think logically about it.

 

[goldstar]

? I had hooked up a bonded generator, it did not trip gfci. Unbonded the generator, it did not trip gfci. ??

There are some generators out there (generally used for job sites) where ALL the receptacles are GFCI protected (that includes the 30A 120/240V one) As soon as you plug the cord in the breaker will trip on the generator. Part of the problem is the HO doesn't know what he's buying, sees a deal on the generator and buys it. Then they call you to install the interlock kit and the problems start.

 

[Dsg319]

IMO floating generators are safer. Unfortunately here in the states we are so obsessed with grounding hardly anyone can think logically about it.

I work a lot in natural gas facilities(hazardous locations)and small bonded portable genset, and they always want a ground rod driven. Always wondered why. Maybe I’m missing the point but off the top of my head I can only think of two reasons.

#1 ( I know ground rods do not clear faults) but maybe having the ground rod near the genset help reduce the potential difference between the gen frame and nearby ground With the ground rod possibly creating a bit of equilpotential around the generator and having a groundfault on a nearby extension cord or tool... possibly idk?

#2 static discharge?

really don’t know the purpose..... sure someone here does.

 

[winnie]

IMO floating generators are safer. Unfortunately here in the states we are so obsessed with grounding hardly anyone can think logically about it.

What is old is new again. For a fun read see appendix A in "Soares Book On Grounding" , "The History and Mystery of Grounding" the benefits of grounded vs ungrounded systems have been debated since the creation of the electrical code.

Given current technology (insulation systems, ground fault detection, automatic generator controls, etc.) the consensus answers might be very different then they were 120 years ago.

Jon

 

[ActionDave]

I work a lot in natural gas facilities(hazardous locations)and small bonded portable genset, and they always want a ground rod driven. Always wondered why. Maybe I’m missing the point but off the top of my head I can only think of two reasons.

#1 ( I know ground rods do not clear faults) but maybe having the ground rod near the genset help reduce the potential difference between the gen frame and nearby ground With the ground rod possibly creating a bit of equilpotential around the generator and having a groundfault on a nearby extension cord or tool... possibly idk?

#2 static discharge?

really don’t know the purpose..... sure someone here does.

Dirt Worshipers are never questioned and never have to defend their obsession with ground rods because the use of them has become so ingrained that no one questions it, just like everyone knows breakfast is the most important meal of the day even though it's not. It matters not that ground rods do nothing, when something goes wrong or a piece of equipment starts acting up the first question that is going to be asked is "Is it grounded?" so, when you are writing specs what matters is you include a ground rod requirement then no one will say you are the one to blame.

 

[Dsg319]

Dirt Worshipers are never questioned and never have to defend their obsession with ground rods because the use of them has become so ingrained that no one questions it, just like everyone knows breakfast is the most important meal of the day even though it's not. It matters not that ground rods do nothing, when something goes wrong or a piece of equipment starts acting up the first question that is going to be asked is "Is it grounded?" so, when you are writing specs what matters is you include a ground rod requirement then no one will say you are the one to blame.

Ha! Sad but true.

 

[SML]

Hi All, I just signed up, seems like a great forum. I searched/researched for hours (actually days) and can't find the specific answers to these questions,:

1. What type of portable generator, bonded-neutral or free-floating neutral, meets code when tied into a service panel with a interlock?
2. I read where some say a free-floating neutral generator is not UL listed and therefore not allowed.
3. Some say if you break the bonded neutral from the generator frame, you void the UL listing.
4. Some say if you don't break the neutral bond on the frame, and also have the bond at the service panel than you risk current back flow and shock especially during damp weather.
5. Wow, so what type of generator can you connect to an inlet that connects to the service panel with a interlock?

I would think the generator manufactures would make the portable generators with a two position switch, if on the home mode, it would power the 30 or 50amp 4-wire receptacle (Free Floating neutral) and disconnect the power and break the bonded neutral to the 120 GFI's, etc. and if switched to field mode, then it would do the exact opposite. Seems like this would solve the problems but being they don't wire the gensets this way what can be utilized to properly connect to to a service panel with an interlock as mentioned above?

It appears that the interlock connection method has been debated for over a decade and no one ever seems to agree on what is acceptable and what isn't. It seems like a no win scenario...

Thank you!