Generator grounding and bonding

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msilva

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We are installing a diesel backup generator and my question is using a ufer ground coming for the generator pad and a half inch eight foot long ground rod will be good enough for bonding the generator case.If there is anything else i am missing please in form me.....
 
Re: Generator grounding and bonding

Also what size wire do i use for the uffer ground or can you give me location of the table in the code book.....thanks guys....
 
Re: Generator grounding and bonding

Are you transfering the neutral? Three phase? Voltage?
 
Re: Generator grounding and bonding

I will be three phase voltage 120/208 volts ...and the transfer switch can switch the nuetral....unsure if we are going to use this feature....can you give me a if we do switch and if we don't switch answer thanks...
 
Re: Generator grounding and bonding

If you switch the neutral, then you will treat the connection similar to a service connection.
You connect the equipment ground conductor and the grounding electrode conductor together with the gounded conductor, bonding to the enclosure.


If you do not switch the neutral, then you will treat the connection similar to a "subpanel".
You connect the equipment ground conductor and the grounding electrode conductor to the enclosure. The grounded conductor is isolated from those connections.
 
Re: Generator grounding and bonding

If you do not switch the neutral, the generator neutral must not be bonded to the generator case, and should not be re-grounded.


Gen10.gif



If you do switch the neutral, (Separately Derived System) the generator neutral must be bonded to the generator case, and must be connected to an acceptable grounding electrode.

If the service has Ground Fault Protection, this configuration is recommended.

Ed


Gen9.gif
 
Re: Generator grounding and bonding

The ufer ground shall not be smaller than a number 4 AWG per 250.52(A)(3). On a similar note the ufer gound will be required to be bonded to the existing building electrode system to form a single electrode system.
 
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