Sub panle

Neutral and equipment ground conductors are combined at sub-panels. Should these be on separate grounding bar bonded?


Typically, yes.

The feeder feeding that panel is URD. Is this a remote panel in a detached building? If so then it is certainly feasible that it is completely legal. In this case the neutral should be bonded.

If it is detached is there a ground rod or other electrode?

Yes Is this a remote panel in a detached building.
I could not fine a ground rod or other electrode

Then that is certainly an issue. A ground rod/electrode has been required at a detached remote panel for years. That one looks quite new.

I believe the 2008 NEC removed this exception, but we always had the option to run a 3-wire feeder to a remote panel in a detached structure IF there were no other metallic paths between structures.
The neutral is bonded just as in a main panel.

This is a general description not including all the details, but gives you the basics.


To be done properly, the terminal bar should be bonded to the enclosure and include a GE, assuming there are no other metallic connections between bldgs.

I’ve said it before, and I’ll say it again - as a home inspector, you should call out anything other than a four-wire feed to a sub panel. There are too many potential “paths” that could make this an improper installation. Let the Sparky sort it out.



if this is the only panel or disconnect at the remote building the panel is required to be rated as service equipment as outlined in 225.36 and will require a main breaker.

I read this as a disconnect in the service equipment, not necessarily at the remote panel. I don’t see it as you’ve interpreted it. Can you elaborate?

Mike is right, and I forgot to mention. ANY remote structure fed from a separate feed requires a form of disconnect.
225.31 and 225.32 would be the NEC references.

I am posting the NEC sections that would apply where more than one building or other structure is on the same property and each additional building or other structure is served by a branch circuit or feeder on the load side of the service disconnecting means.

225.31 Disconnecting Means.
Means shall be provided for disconnecting all ungrounded conductors that supply or pass through the building or structure.

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.

This is saying that a remote building is required to have a disconnect that disconnects all hot conductors and this disconnect is required to be rated as service equipment.

There is no panels on the market that is rated as service equipment that does not have a main breaker.

It is possibel to install a knife disconnect and this panel as long as the knife disconnect is rated as service equipment.

The requirement for the disconnect to be rated as service equipment will stop the installaton of six single pole breakers as no panel is listed as service equipment with this type installation.

But that disconnect is not required to be located in the detached building. That disconnect can be located in the service equipment - the “main” building.

In other words, the disconnect serves the feed to the remote panel and protects the conductors running from one building to the next.

Here the code says where that disconnect MUST be located;

225.32 Location.
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors. For the purposes of this section, the requirements in 230.6

When we hit the remote building we must install a disconnect that is rated as service equipment either inside nearest the point of entry or outside the building.

What you are talking about is the overcurrent device installed to protect the conductors after they leave the panel located at the first building and this overcurrent can not replace the requirements found in 225 Part II for what must be installed once the conductors arrive at that building.

Part II of 225 is one of the most important sections for feeders and branch circuits that supply remote buildings. It is also one of the wrose enforced sections when it comes to the installation of back up generators.

Interesting. I will have to look into this further. Rarely have I seen this type of setup, but it seems pretty clear as to the intent.

Thanks for the info.

If the CB on the right side is from a different company, that may be considered as a defect. Does the label indicate this?