Exfrmer+panel-Revised

[Toros]

Hi
I am upgrading exist. 400A, 3ph, 120/240v service
to 600A, 3ph. 480v , 3w.

is attached designed- by- myself plan looks ok to you??

tanx

Hi,
I revised my design. (refer to attached...)
would you check all again thoroughly.

Specially: feeder, xfrmer grounding sizes & primary o.c.p.d

 

[iceworm]

Looks good - I like the bollards.

You likely have really good reasons for locating the equipment as you have shown. I can't tell. So some questions I would have are:

I don't see any 480 panel - Are there no 480V loads?

If not, why the 600A service? The transformer needs a 225A feed - unless it is something really high inrush like a TENV. What are you using for the transformer feeder CB?

Why not locate the transformer and 208 panel inside the building nearer the loads? Maybe even two smaller transformers and panels located at opposite ends of the building?

And, if the answers are, "Cause that's the way we want it." That's good enough.

Not connected to the above: I suspect you are still working on a oneline showing the loads, available SSC, maybe even arc flash.

ice

 

[augie47]

IMO:
Per 240.21(c)the 500 kcmil to your 400 amp panelboard are undersized.
Your system bond jumper between your transformer and panel is undersized.
Using EMT vs PVC to enclose your GECs brings about a whole world of problems

 

[Joe Villani]

Grounding Electrode Conductor undersized (Depending on the electrode used)

Depending on the code cycle don't forget the primary disconnect.


Joe

 

[hbendillo]

Like iceworm said, I wouldn't purposely locate panelboards outdoors unless there is just no room inside. You are going to have to run a lot of branch circuits through the wall and buy NEMA 3R rated panelboards. You must be adding a lot of loads to the building to upgrade from a 400 Amp 120/240 3PH service to 600 amp 480 volt 3PH. Unless you actually are feeding some 480 volt loads in the building you are spending additional money for a 480-volt service to step down to 120/208. Just get a 120/208 volt service drop.

 

[augie47]

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