Portable Generators Grounding

[Mike01]

How are portable generators grounded small single phase installations, I have seen some that have four wire service conductors (from the generator to the facility) with 2?, 1N, 1Grd. Is this treated as a SDS are the N & Grd. tied togerther at the gen? if so how is it grounded typically to the frame as it sits on the ground? Or is the Grd. Strictly a equipment Grd. With no connection to the grounded conductor at the portable generator? I saw one the other day and it got me thinking???:roll:

 

[M. D.]

from the link
https://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/Neutral-to-GroundConnections~20020521.htm

Generator ? If the grounded (neutral) conductor in a transfer switch is not opened, then the grounded (neutral) from the generator will be solidly connected to the utility?s service grounded (neutral) conductor. Under this condition, the generator is not a separately derived system, and a neutral-to-case bond shall not be made at the generator or at the generator disconnect [250.20(D) FPN 1].

If a neutral-to-case bond is made at both the generator and generator disconnect, then objectionable neutral current will flow through metal raceways and grounding and bonding path to the power supply.

and here is a thread you might find worth reading ,..there are a couple of links you might want to check out

 

[jwelectric]

250.34 Portable and Vehicle-Mounted Generators.
(A) Portable Generators. The frame of a portable generator shall not be required to be connected to a grounding electrode as defined in 250.52 for a system supplied by the generator under the following conditions:
(1) The generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
(2) The normally non?current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are connected to the generator frame.