There is an existing 240D service, it is proposed to install a 240D-208Y120 transformer to supply a bunch of 120v loads. There is an existing conduit and conductors (3xH+1xG) from the service to the location where the transformer would go (about 100ft away). Does there need to be a seperate GEC from the transformer back to the service in addition to the EGC? There is no building steel to bond it to.
transformer GEC
- Thread starter wireguru
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kevin
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- Post Falls, ID
No.
The GEC for the new transformer shall connect to the nearest of two grounding electrodes: underground metal H2O pipe or structural metal per 250.30(A)(7)(1) and (2).
If neither are available, Ex. 1 requires the use of any other electrode identified in 250.52(A).
Your post says that building steel is not available, so underground metal H2O pipe, if available, MUST be used as the grounding electrode. Assuming no such electrode exists, the best alternative probably is to drive (2) ground rods for the required grounding electrode [250.52(A)(5) and 250.56].
The GEC for the new transformer shall connect to the nearest of two grounding electrodes: underground metal H2O pipe or structural metal per 250.30(A)(7)(1) and (2).
If neither are available, Ex. 1 requires the use of any other electrode identified in 250.52(A).
Your post says that building steel is not available, so underground metal H2O pipe, if available, MUST be used as the grounding electrode. Assuming no such electrode exists, the best alternative probably is to drive (2) ground rods for the required grounding electrode [250.52(A)(5) and 250.56].
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