Grounding Electrode Conductors

[illmetro]

I recently stumbled across an installation SDS transformer 480 - 120/208 30 KVA, with no GEC in either the transformer or the first panel after transformer. Also inside my transformer XO only has 1 wire the neutral for the low voltage panel. Inside the low voltage panel the bond screw that make neutral and ground one is installed. For some odd reason I feel like this connected incorrectly. Any input would be appreciated.

 

[ActionDave]

Welcome to the forum.

If I understand you correctly there is a bonding screw in the panel of the secondary of the transformer and the grounding electrode conductor is missing. That would mean the GEC would need to land in the panel as well but we would need more information about why it's missing to say anything more about what's right or wrong about the installation.

 

[augie47]

The install you describe would require a grounding electrode and, as Actiondave, points out, it should be connected at the panel as that is where your bond is located. YOu would also need a system bonding jumper between the transformer case and the panel (this could be a 250.118 acceptable conduit)

 

[illmetro]

GEC

GEC

Thank you for your input on this issue. For a little more clarification this panel is inside a walkable ceiling above our process areas that actually has a few transformers up there for step down purposes. During my inspections like noted above I have NO GEC in the panel on any of my transformers except 2 in our entire facility, ( I would be safe to say eight at least). Now I guess I'm wondering why no GEC was installed originally. The reasoning behind this is on that low voltage panel I have a single circuit feeding three GFCI's for computer, scale, and printer. The weird part is it only trips the GFCI but very randomly and only I Friday when we use that side of our facility. We used an extension cord that was fed from a different panel and no GFCI tripping occurred. I curious could this be related to the missing GEC?

 

[infinity]

IMO the missing GEC has nothing to do with it as long as the system bonding jumper is installed.

 

[petersonra]

I recently stumbled across an installation SDS transformer 480 - 120/208 30 KVA, with no GEC in either the transformer or the first panel after transformer. Also inside my transformer XO only has 1 wire the neutral for the low voltage panel. Inside the low voltage panel the bond screw that make neutral and ground one is installed. For some odd reason I feel like this connected incorrectly. Any input would be appreciated.

I think what you have described is OK as far as it goes.

I do think you need a GEC connected to the neutral bar in the panel.