3 phase 208/120

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easymoney

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If you have a 3-phase 208/120Y transformer do you have to bring a seprate grounded and grounding conductor to the service panel, or can you bring one and bond them in the service panel?:-?
 
Are you talking about a POCO transformer to the service?

250.26(3), no EGC.
 
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easymoney said:
No it is a small 30kva 480 delta to 208/120y
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If I understand your question correctly, you are permitted to bring the grounded conductor (neutral) from the transformer to the panel, and the grounding electrode conductor from the grounding electrode to the panel, and bond the neutral to ground at the panel. See 250.30(A)(1) & (A)(3).
 
So if i understand 250 (A) (3) correctley you bring your grounded conductor from the transformer to the breaker panel and the grounding electrode conductor to the grounding lug in the breaker panel and then bond them together in the panel with the system bonding jumper
 
easymoney said:
So if i understand 250 (A) (3) correctley you bring your grounded conductor from the transformer to the breaker panel and the grounding electrode conductor to the grounding lug in the breaker panel and then bond them together in the panel with the system bonding jumper
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Grounding conductor is bonded to the XO terminal at the transformer.
 
easymoney said:
So if i understand 250 (A) (3) correctley you bring your grounded conductor from the transformer to the breaker panel and the grounding electrode conductor to the grounding lug in the breaker panel and then bond them together in the panel with the system bonding jumper
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Thats is one way to do it but since you have to bond the transformer enclosure anyway (250.4(A)(2)) I usually put the EBJ in the tranny and bring the GEC there also. That bonding strap you will see in the tranny only bonds the core frame to the enclosure because the two are separated but isolation pads.
 
I think i have it. Connect the XO in the transformer to the grouned lug in the breaker box . The the grounging electrode conductor bond to the transformer and then to the grounding lug of the breaker box
 
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