I have a new remote structure, fed from the main building, on a concrete pad. The contractor ran 480v, then a wp step down transformer to 120/208 and a new panel. Two new ground rods were added. Should there have been a ufer because it's a separately derived system?
Ufer for seperately derived system
- Thread starter Danielt
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hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Is this a new pad? Or existing? If new, they should have installed it before it was poured, (assuming enough rebar of the correct size) or turned up a piece of rebar inside. If existing, it is not required to break the concrete to attach. If existing, the two ground rods are sufficient.
- Location
- New Jersey
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- Journeyman Electrician
Would rebar in a concrete pad qualify as a CEE?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
Welcome to the forum.
There should be an electrode (system) because it's a separate structure and because it's an SDS.
An Ufer is one type of electrode, but it must be in a reinforced footing to qualify, not just a pad.
In my pinion, the two rods are adequate. You do have a local disconnecting means, don't you?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
No, it needs to be in a footing to qualify as an electrode.
hillbilly1
Senior Member
- Location
- North Georgia mountains
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- Owner/electrical contractor
The op said structure, so I would assume it would have a footer, but not enough info from the op at this point.
There is a disconnect, and I agree the ground rods are sufficient. After all, it is still bonded back to the main building also.
It's only a 6 inch pad, but it does have rebar..
I've been considering if a separately derived system , including generators where the ats switches the neutral, should have a ufer if available.
- Location
- New Jersey
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- Journeyman Electrician
Since it's just a transformer pad it cannot be used to make a CEE. The two ground rods would be sufficient to make a GES for the transformer.
CrazyWabbit
Member
- Location
- Fort Worth TX
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- Engr
it depends on AHJ. in fort worth you are required to have UFER ground (or CU plumbing) and a ground rod... two ground rods will not cut it.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
That would be something that is not required by the NEC. Is that a written code amendment or just the way they want it done?
Tulsa Electrician
Senior Member
- Location
- Tulsa
- Occupation
- Electrician
I read it as:
Separate structure.
Feeder from main building.
Transformer out side of separate structure. He said "wp"
Transformer on concrete pad?
Separate structure on pad, no footing?
Type of structure, metal wood etc?(just curious on that on). May need equal potential plane.
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