So my question, for everyone is about my ground rod, either being on the service disconnect before the transformer as my local authority recommends, or should I drive my ground rod run my number six to the transformer, ground lugs, and then back to the disconnect that is feeding the step down transformer. Step down transformer is a 45KV480 V Y down to 2083 phase, my feeders are coming from the building on the other side of the property underground to a 480 V service disconnect with just the AB and C phase conductors as well as my ground. So is it recommended that I drive a ground rod near my disconnect and run an additional number six from the ground rod to the service disconnect, which would be on the primary side before the transformer, and then out of the disconnect to the transformer and continue it all the way through to the new load center?
Transformer grounding
- Thread starter Roscoe
- Start date
- Occupation
- Licensed Electrician
You land your #6 Grounding Electrode Conductor either in the transformer or at the first disconnect on the secondary side. You don't need anything to primary disconnect other than the Equipment Ground that is run with the feeder.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
So for clarity this is not a service disconnect because the primary of the transformer is fed by a feeder from the building and there is no neutral. This terminology is important because an actual service disconnect would have different grounding and neutral requirements than just the disconnect on the transformer primary. As Dave stated the EGC for the primary disconnect would just get the EGC landed within the disco. The GEC will land wherever you're installing the SBJ.
Would anyone argue that this is a separate structure therefore the primary disconnect needs to be connected to the GES?
Certainly no harm in doing so but I wold consider it "equipment" and not required.
ptonsparky
Tom
- Occupation
- EC - retired
Certainly.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I think the argument that this is a structure is a pretty good one.
ptonsparky
Tom
- Occupation
- EC - retired
I picture a feeder from the main bldg to the transformer three primary one EG to transformer on pad. Three secondary phases, one neutral (floating) and one EG to remote structure. Secondary Neutral bonded at the SE with a GES established there.
But it could be done differently.
But it could be done differently.
Old man didn't see the "elephant in the room" in the 1st post. Now that my eyes have awakened for the day, I agree, primary GES required.I think the argument that this is a structure is a pretty good one.