Generator/Transfer Switch Question –When to use a bonded neutral?

[olc]

Choosing between generators with bonded neutral and floating neutral:

When do you use generator with a bonded neutral (and transfer switch with switched neutral) (separately derived )?

When do you use a generator without the neutral bonded? Is this more common for midsize (commercial) installations?

 

[ggunn]

The neutral is never floating; it's bonded to ground on one side of the transfer switch or the other.

 

[tom baker]

The neutral is never floating; it's bonded to ground on one side of the transfer switch or the other.

And where it is bonded determines the type of transfer switch.

 

[LarryFine]

Usually, the answer is to match the normal source.

 

[augie47]

Here is an EC&M article covering the subject:

https://www.ecmweb.com/content/article/20893255/unraveling-the-confusion-over-generator-power-and-neutral-conductors

It appears you switch the neutral when you have GF on the supply side.

 

[tom baker]

For dwelling units, the most common portable generator is the bonded neutral type, which should be used with a neutral transfer switch, otherwise if granny has gfci protection it will trip. The most common type xfr switch for home use does not xfr the neutral, the Jenny would need to be floating neutral, and that type can not be used standalone.
Also please see art 702 for required inlet labels

 

[suemarkp]

the Jenny would need to be floating neutral, and that type can not be used standalone.

Is this some recent rule, or just an OSHA rule? My portable (although it is 15KW) is floating neutral. Many other smaller portable generators people have are floating neutral. None of these have GFCI on the larger outlets (30A or higher) either.