Outdoor Transformer Grounding]

[corvalan]

This is an Electrical Grounding questions (NFPA 70 2017).
*
I have an*OUTOOR*Delta-Wye transformer feeding a building.
*
The neutral terminal at the secondary is connected to the metallic frame of the transformer through a copper conductor and using a good connector at the frame.
*
There is another connector attached to the frame. An uninsulated copper conductor is connected to the frame and to a grounding electrode in close proximity of the transformer.
*
Therefore, the neutral terminal is indirectly connected to the grounding electrode.
*
In other words, the neutral terminal it is not directly connected to the grounding electrode through a continuous*"grounding electrode conductor".
*
Question:* Is this installation satisfying the NEC Article 250 requirements?
*
Just to clarify this question.
*
This installation is in an OUTDOOR transformer.
The installation requirements of the "grounding electrode conductor" that are specified for the service equipment do not apply to this outdoor*location.
*

 

[augie47]

From my point of view:: If it's a utility transformer the the NFPA70 NEC rules would not apply (I have no reference on their Code).
If its a customer SDS, 250.30(B)(5) states: . This connection shall be made at the samepoint on the separately derived system where the systembonding jumper is connected and IMO, that would require a direct connection.

 

[PVfarmer]

here's a pic

here's a pic

(NFPA 70 2017).
*
I have an*OUTOOR*Delta-Wye transformer feeding a building.
*
The neutral terminal at the secondary is connected to the metallic frame of the transformer through a copper conductor and using a good connector at the frame.
*
There is another connector attached to the frame. An uninsulated copper conductor is connected to the frame and to a grounding electrode in close proximity of the transformer.
*
Therefore, the neutral terminal is indirectly connected to the grounding electrode.
*
In other words, the neutral terminal it is not directly connected to the grounding electrode through a continuous*"grounding electrode conductor".
*
Question:* Is this installation satisfying the NEC Article 250 requirements?
*
Just to clarify this question.
*
This installation is in an OUTDOOR transformer.
The installation requirements of the "grounding electrode conductor" that are specified for the service equipment do not apply to this outdoor*location.
*

From my point of view:: If it's a utility transformer the the NFPA70 NEC rules would not apply (I have no reference on their Code).
If its a customer SDS, 250.30(B)(5) states: . This connection shall be made at the samepoint on the separately derived system where the systembonding jumper is connected and IMO, that would require a direct connection.

I'll admit it- I'm still a bit stumped.
Trying to go by Fig.2 from this link...the green text quoted is what Fig. 2 calls the SBJ and the blue quoted text would be the GEC?

So when "the GEC should be connected where the SBJ is connected..."-- that's TWO places- the XO terminal and the xfmr frame.
So in Fig. 2, the GEC (brown line with ground symbol?) is connected to the XO, *not* the frame.
If so, the orange quoted connection should be from secondary XO to the grounding electrode in close proximity, and not the xfmr frame?

One other thing- there is a limit on the "proximity" there, correct?

Stumped by the Code? NEC Requirements on Grounding Electrode Requirements for Separately Derived Systems

http://ecmweb.com/qampa/stumped-cod...-requirements-separately-derived-systems-and-

 

[electrofelon]

From my point of view:: If it's a utility transformer.....

+1 That is the key thing we need to know.

 

[PVfarmer]

Originally Posted by augie47

From my point of view:: If it's a utility transformer.....

+1 That is the key thing we need to know.

Howdy!
When the OP said:
The installation requirements of the "grounding electrode conductor" that are specified for the service equipment do not apply to this outdoor*location.

I'm thinking it is not owned by the utility, because when he says the reqs. of 250 "do not apply to this outdoor location", to me it implies that the xfmr could possibly go inside as well, and any utility xfmr would not go inside.

 

[electrofelon]

Originally Posted by augie47

From my point of view:: If it's a utility transformer.....



Howdy!
When the OP said:
The installation requirements of the "grounding electrode conductor" that are specified for the service equipment do not apply to this outdoor*location.

I'm thinking it is not owned by the utility, because when he says the reqs. of 250 "do not apply to this outdoor location", to me it implies that the xfmr could possibly go inside as well, and any utility xfmr would not go inside.

And the way I read it is more likely to be a utility transformer LOL.......Hopefully the OPer will get back with clarification.