I’m doing an inspection and got my hands on a prelisting report. The previous inspector called this out for not having bonding provisions for the metal raceway. To me, it looks like it has pretty good connectivity to the metal panel enclosure which is grounded.
Since there are service entrance conductors within that service raceway it needs to be bonded by something other than a standard locknut which is what is visible in the photo. If there are concentric or eccentric KO’s (there are concentric KO’s on the meter enclosure) then a bonding bushing is required. Only one side of the raceway requires the additional bonding so in this case a bonding bushing could be in the meter enclosure. If there are no concentric or eccentric KO’s then a bonding locknut is permitted in lieu of a bonding bushing. Looks like there are some other issues as well.
When a breaker is back-fed, it is supplying power to the panel and is required to be secured to the panel. If it comes loose, the breaker is still energized.
Hi Robert, how could/would/should a home inspector identify if the required additional bonding is in the meter enclosure, thus not erroneously calling out missing bonding?
Good question. Most meter enclosures are locked so they cannot be accessed. For a home inspection I would simply report what is visible (in this case no additional bonding) and defer to an electrician.
I agree it looks like it comes from the meter. Could be:
a bonding jumper to the meter enclosure/neutral bus (or what someone thought was an EGC) or
a bonding jumper to a bonding bushing on the raceway inside of the meter.
The 1) would not be permitted because it is in parallel with the neutral. This would create objectionable current and is a violation of 250.6(B). When the metallic meter enclosure is ahead of the service disconnect it is bonded directly to the neutral. The neutral in the panel is also bonded via the MBJ (green screw). Since both metal enclosures are bonded to the neutral there is no need to run a 4th conductor (the bare #8) between the two enclosures. (Think of a 3-wire SE cable typically run between the two which is code compliant).
Unless the bare conductor in question is providing the require bonding of the metal raceway via a bonding bushing inside of the meter enclosure it should be removed. Now having said all of that not removing it might never cause any issues.
Great to know! I knew there was something about parallel path but again the specifics were beyond me…until now.
I see that jumper configuration a lot in our area & have been inclined to think it is a bonding jumper to a bonding bushing on the raceway inside of the meter. Obviously, I cannot ever confirm its use since we don’t access meter box so I report the raceway & defer to an electrician.
You can’t report what you can not see. Always assume everyone did their job correctly until you SEE differently. It’ll save you from a lot of complaints.