Sub panel is bonded and has no ground from main panel

[Gomer12]

I have a sub panel that appears to be bonded. Also, the neutral and ground wires are connected. The is no ground going from the main panel to the sub panel. I know that sub panels should not be bonded.
Looking for a second opinion on this.
Both are Siemens panels.

 

[infinity]

By bonded you mean that the neutral is bonded to the enclosure? Is this in a separate structure?

Welcome to the Forum.

 

[ggunn]

If the panel is fed by a feeder as opposed to service conductors, neutral and ground should not be bonded.

 

[winnie]

To be perfectly clear:

In general, for a 'sub panel', the neutral must _not_ be bonded to the enclosure, ground, or EGCs. (I say in general because there used to be a big exception.)

At the same time, there _must_ be a fault current path that connects any EGC or bonded metal to the system neutral (or other grounded conductor).

If you have a subpanel that 1) doesn't have an EGC run with the feeder and 2) has the neutral bonded to the enclosure, and you proceed to remove the neutral bond, you take a likely code violation and turn it into a major safety hazard.

The exception used to be for detached structures. If you met various requirements you could bond neutral to ground at the detached structure and not run an EGC with the feeder. This is not longer allowed but may be grandfathered at a location.

 

[Seven-Delta-FortyOne]

^^^ What Winnie said.

There was time a time it was allowed to run 3-wire feeder to a detached structure, if there were no parallel conductive paths between the structures, i.e., metal water line or gas line.

That exception is no longer allowed, but there are thousands of existing installations like that. Unless the home owner is going to open the walls or trench between buildings, and run a new 4 wire feeder, you're kind of stuck with it.

Unfortunately I run into this quite a lot. I see 3 wire feeders to attached and detached garage sub panels all the time. I don't know who was doing it like this or how it was passing inspection, but there it is.

I did a transfer switch replacement where they had not 1 but 2 sub panels with redundant N-G bonds, and they also had a N-G bond in the ATS. All in the same structure. Not much I could do about it besides remove the bond in the new ATS I installed, run an EGC to the sub panel, and call it good.