Transformer bonding

[Brandon Loyd]

I found a transformer where instead of landing the neutral and grounding electrode conductor on the XO, they looped the grounding electrode conductor through the XO lug, then landed the GEC and neutral on a lug attached to the case. Is this legal? I've never seen this before. I attached an image if it helps.

 

[augie47]

Ignoring other questionable practices for the moment, it appears there is a "weak link in the chain".. The neutral seems to be larger than the GEC feeding it. What size wire is required for the neutral load ?

 

[Brandon Loyd]

The GEC is #8 and the neutral is #4.

 

[Smart $]

As connected, the grounded conductor is used for equipment bonding. That is only permitted on the line side of service equipment.

 

[Brandon Loyd]

Assuming the neutral is size properly. In this picture, would I be right in saying the smaller EGC is acting as the neutral for a short section, therefore it could possibly become overloaded? If not, what is the code violation is shown in this picture in regards to the neutral and EGC installation?

 

[Smart $]

Assuming the neutral is size properly. In this picture, would I be right in saying the smaller EGC is acting as the neutral for a short section, therefore it could possibly become overloaded? If not, what is the code violation is shown in this picture in regards to the neutral and EGC installation?

Yes to the first question [220.61 for starters]. Another violation is as I mentioned above, irregardless of the conductor size... don't know the section offhand.

 

[Brandon Loyd]

Ignoring other questionable practices for the moment, it appears there is a "weak link in the chain".. The neutral seems to be larger than the GEC feeding it. What size wire is required for the neutral load ?

Neutral is a #4, GE is a #8. Are you saying that the GE can't be smaller than the Neutral?

 

[RUWired]

If not, what is the code violation is shown in this picture in regards to the neutral and EGC installation?

The article is 250.24(A)5.and 250.30(A)

Rick

 

[Smart $]

Neutral is a #4, GE is a #8. Are you saying that the GE can't be smaller than the Neutral?

NO.

The conductor running from X0 to transformer enclosure, as wired in the picture, is serving as a neutral conductor and as a system bonding jumper. It is undersized if: "Assuming the neutral is size properly" and I assumed correctly that you were referring to the larger conductor connected to the transformer enclosure with white tape on it. Ergo, if the conductor with white tape is properly sized, the jumper from enclosure to X0 is undersized.

The other violation I referred to is that on the load side of a service(s), a grounded conductor cannot be used as a grounding conductor... typically. IIRC, there is at least one exception for which a typical installation never qualifies.

If the white-taped conductor were to be lifted from its current termination point then landed on X0, everything would be fine (assuming all conductors are properly sized and terminations solidly connected).