Zig Zag gounding xfmr for 100KW ground mount array

[Giark]

The utility is requiring a zig zag grounding xfmr for a 100kw ground mounted array. I have xfmr sizing from them. I know there is a protective relay required to make this setup work. I imagine there are a variety for ways to accomplish this. In hopes of not reinventing the wheel does anyone have a preferred method/ components that work? Thanks, John

 

[electrofelon]

The utility is requiring a zig zag grounding xfmr for a 100kw ground mounted array. I have xfmr sizing from them. I know there is a protective relay required to make this setup work. I imagine there are a variety for ways to accomplish this. In hopes of not reinventing the wheel does anyone have a preferred method/ components that work? Thanks, John

Interesting. I dont quite follow though. Where is the zig zag to go? Is there already an ungrounded service supplying the site that this will be tied into?

 

[GoldDigger]

There is another thread about a POCO which is requiring a zig-zag grounding transformer even though the service itself is a grounded wye. There was never a good engineering explanation for that requirement.

 

[jim dungar]

There is another thread about a POCO which is requiring a zig-zag grounding transformer even though the service itself is a grounded wye. There was never a good engineering explanation for that requirement.

Most of the time, the issue involves the 'distributed generator' becoming 'islanded' from the utility grounded-wye system.


Generically the term is 'artificial neutral'. A Zig-Zag is simply one style of 'grounding transformer',another common one is often called a 'wye-delta'.
Impedance grounding, like HRG, is a separate issue from providing a ground reference.

 

[GoldDigger]

Most of the time, the issue involves the 'distributed generator' becoming 'islanded' from the utility grounded-wye system.

Which was somewhat odd given that the distributed generation in question was a grid tie inverter array which automatically shuts down when islanded.

 

[jim dungar]

Which was somewhat odd given that the distributed generation in question was a grid tie inverter array which automatically shuts down when islanded.

Are you saying someone didn't look at all the details before making a judgement?:blink:

 

[GoldDigger]

Are you saying someone didn't look at all the details before making a judgement?:blink:

I think that I am saying that once the rule was written it was no longer anybody's job to see whether it made sense.

 

[jim dungar]

I think that I am saying that once the rule was written it was no longer anybody's job to see whether it made sense.

:slaphead:

 

[excel]

Solution for Effective Grounding

Solution for Effective Grounding

The utility is requiring a zig zag grounding xfmr for a 100kw ground mounted array. I have xfmr sizing from them. I know there is a protective relay required to make this setup work. I imagine there are a variety for ways to accomplish this. In hopes of not reinventing the wheel does anyone have a preferred method/ components that work? Thanks, John

Hello Giark, I have a following solution which you might like to use for this application.
See if it make sense for you.