St neutral/ground

[Honda lee]

Should the neutral on st winding be grounded? Or should you just have a case ground?

[Henry W]

Welcome aboard Honda lee!

Here is some info to read.

Portable and stationary generators are covered.

http://www.utterpower.com/generator_grounding.htm

https://www.osha.gov/OshDoc/data_Hurricane_Facts/grounding_port_generator.pdf

http://www.cumminspower.com/www/literature/technicalpapers/PT-6005-GroundingAC-1-en.pdf

http://www.cumminspower.com/www/literature/technicalpapers/PT-6006-GroundingAC-2-en.pdf

http://www.usbr.gov/power/data/fist/fist5_13/5-13.pdf

[Honda lee]

Thanks for the info it helps a lot

[veggie]

Not so simple...

I think it depends on your intentions for the generator.
A home electrical system should have only ONE point where the neutral is bonded to ground.
In most houses, this is already done in the main entrance panel.

If you intend to power your house via a transfer switch, you may have to leave the neutral on the ST head "floating".
By design, the ST heads already have a floating neutral while most 3600 rpm light duty heads have a "bonded Neutral" because they are typically used in portable applications and by definition serve as the entrance panel (being the primary source of the portable power).

So, to properly answer your question you should also state the intended service for the ST head as well how you would like it connected to your system.

cheers,
veggie

[BruceM]

+1 Veggie's right on the mark comment.
Multiple earthing of the ground, along with multiple neutral/ground connections are very common code violations, and they cause very elevated magnetic fields, as well as potentially unsafe ground voltages and current.  

The Wye power distribution system is itself a horrible violator of good engineering practice, with the neutral jumped around each customer transformer and distribution line transformer. The neutral is then earthed or grounded every few poles and at every junction box or transformer, plus on the customer side at the well and panel, often bonded to water and gas mains.  This creates many alternate paths for the neutral current to return to the power plant through the earth and aquifer(s).  One power engineering text I have states that around 25% of the return current at a coal fired plant was coming through the cooling pond pipes, returning through the earth.  This net current not on the wires causes widespread magnetic fields in Wye connected towns and rural areas, that does not exist in Delta served areas.  Delta distribution has all customers transformer isolated, with no multipoint grounding of distribution and is a proven system that follows decent engineering practice.  Delta served residential areas measure about 1/100th of the magnetic fields.  

[Henry W]

Grounding Permenant and Portable setups are differant most of the time.

There is lots of info in the reading I provided, I posted the links because I did not want to give false info. As you will see it can get confusing to some.
It depends on your application, your local and/or state government, your equipment manufactures and the NEC.

Henry

[Honda lee]

Thanks , for all the info I have worked with electric in my work for 27 years as a refrigerantion/ HVAC tec but new to generators and didnt want to short anything.

[buickanddeere]

  Depends . The idea is to not carry neutral current on the ground system