My favorite grounding

[Inspectorcliff]

Gentlemen, been a while, Hope all is well. New topic, (acutally old topic revisited). Separately Derived systems, Here is the picture. Utilities xformer, to the typical 120/240 single phase service. Feeder to a step-up xformer, 240Pri/ 480 Secondary. This feeds a controller for pivot sprinkler system.
QUESTION: What is line and what is load? What is separately derived system?When do we bring a grounded conductor to the separately derived system?
In a nutshell, Is the sparately derived system to be treated like service entrance equipment? I can see where depending on the application, that it could or could not be. Thanks.

 

[Pierre C Belarge]

Gentlemen, been a while, Hope all is well.
Good to see you back.
New topic, (acutally old topic revisited). Separately Derived systems, Here is the picture. Utilities xformer, to the typical 120/240 single phase service. Feeder to a step-up xformer, 240Pri/ 480 Secondary. This feeds a controller for pivot sprinkler system.
QUESTION: What is line and what is load?
Primary side is line, Secondary side is load.
What is separately derived system?
The transformer is a separately derived system.
When do we bring a grounded conductor to the separately derived system?
In regards to the transformer, it is not required.

In a nutshell, Is the sparately derived system to be treated like service entrance equipment?
No, but grounding on the secondary side to the 1st disconnect may be similar.
I can see where depending on the application, that it could or could not be. Thanks.

...........

 

[Inspectorcliff]

Pierre

Pierre

...........

Pierre, thanks for being so kind to do the enlightening. I believe what you are saying and it appears to me as such. BUT, one of my inspectors came up with the question, and I think he is calling 250.24 A), I don't feel a feeder to aquire a separately derived system, is to be treated the same as service entrance. Granted Pri is line, Sec is load, But, his logic is, we now have a new service, tying the grounding and grounded circuit conductors together at the first point off of the step-up transformer. I don't think we do. Give me a code reference for this part of your statement, please. What is separately derived system?
The transformer is a separately derived system.
When do we bring a grounded conductor to the separately derived system?
In regards to the transformer, it is not required.

 

[ericsherman37]

Pierre, thanks for being so kind to do the enlightening. I believe what you are saying and it appears to me as such. BUT, one of my inspectors came up with the question, and I think he is calling 250.24 A), I don't feel a feeder to aquire a separately derived system, is to be treated the same as service entrance. Granted Pri is line, Sec is load, But, his logic is, we now have a new service, tying the grounding and grounded circuit conductors together at the first point off of the step-up transformer. I don't think we do. Give me a code reference for this part of your statement, please. What is separately derived system?
The transformer is a separately derived system.
When do we bring a grounded conductor to the separately derived system?
In regards to the transformer, it is not required.

If the transformer primary doesn't need a grounded conductor then it doesn't need one. But if it is creates a neutral on the secondary side, then I believe you would treat it as an SDS and bond the secondary neutral to the EGC somewhere between the secondary terminals and the first disconnect with a system bonding jumper.

 

[Inspectorcliff]

well

well

Now, that I can buy, I believe that is the intent of the Code. If all I am trying to do is step it up and keep it 240 v/pri and 480 v/sec, all single phase, I think the equipment grounding conductor, the electrode conductor at the control panel, all bonded together on a terminal strip, strategically located, Would meet the requirements. Yes???