A lot of portable generators have the white wire tied to the bare/green ground; that is the grounded conductor is tied to the grounding one.
This makes the generator a "separately derived power source", which needs special treatment. The underlying issue is that (for safety reasons), the grounded and grounding conductors can only be tied at one point, and that point is just after your main disconnect, which is usually your main panel. If you notice, any subpanels have the tie removed (as it should). There are two possible ways to correctly handle this. One is to have a subpanel with a three pole two position "disconnect". Both poles and the white (neutral) would need to be switched. One position would connect to a feed from the main panel, the other would need to connect to the generator. This method would require a dedicated grounding rod to be connected to the generator. The other, and simpler method is to disconnect the tie between the grounded and grounding conductors in the generator circuitry (if possible). No additional ground rod is needed. To be truly correct, you would still need to use either a two pole two position "disconnect" type switch (without switching the neutral), or more properly to use a separate feed breaker for the generator input (using a breaker that is appropriately rated for the generator!) and a panel faceplate that physically prevents both the breaker on the feed from the main panel and the feed from the breaker from being on at the same time. In either case, the input to the house from the generator should accept the receptacle end of an extension cord so as to prevent any attempts to use the input as a normal circuit. (Don'tcha love code compliance?) You'll probably want to verify the above with a local electrician, but based upon my limited understanding of the code as a layperson, the above methods should be largely correct. YMMV, IANAL, and all the usual disclaimers... -j. -- John W Reames [email protected] Home: +14106646986 Mobile: +14437915905 > On Sep 12, 2014, at 11:38, Dan Penoff via Mercedes <[email protected]> > wrote: > > I'm not sure why they would have a 120/240 socket without the genres to being > wired that way. > > If you have the cover off the junction box it would be easy enough to check. > > The generator is a four lead machine, so there will be four large wires > coming out typically labeled 1,2,3 &4. 1 and 2 are one stator winding, 3 and > 4 are another. > > If they are connected in parallel, the generator is wired for straight 120v. > If they are wired in series and the common connection between the two is > grounded and/or tied to the neutral, it's a 120/240v setup. > > Dan > >> On Sep 12, 2014, at 10:41 AM, Mitch Haley <[email protected]> wrote: >> >> One last question. >> If my four pole twistlock outlet is labeled 120v/240v, is there any need to >> test the generator, or is it safe to just assume you can power a 120v/240v >> breaker box with it? (I've heard that some generators don't have a solid >> neutral that splits the 240v outlet into two safe 120v halves, and the way >> to test it is to try to run a 120v light bulb off one leg of the 240v outlet) >> >> Mitch. > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > All posts are the result of individual contributors and as such, those > individuals are responsible for the content of the post. The list owner has > no control over the content of the messages of each contributor. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com All posts are the result of individual contributors and as such, those individuals are responsible for the content of the post. The list owner has no control over the content of the messages of each contributor.
