Parallel path???

yellowtruck29

Member
Location
Akron ohio
Occupation
inspector
I am hoping to see who may have some good knowledge about parallel paths between meter socket and the 1st means of disconnect. I seen a job recently where there was a supply side bond jumper ran between the meter socket and the 1st means of disconnect with a connection to neutral at each end and bond bushing on each end with emt on one side to flex on the other side. I say this is objectional current and could be dangerous cause I'm pretty sure the neutral current will take both paths. What is some input on this ?? Thanks
Is there any online testing or information I can find to prove this ?? We seem to have some disagreement on this 🤔
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
A metallic service raceway would be permitted to be bonded by a single SSBJ. It is only required on one side. Objectionable neutral current will flow on the metallic raceways with or without the bonding jumpers on both sides. One could argue that 250.6 would require you to remove the SSBJ on one side of the service raceways but since you have both EMT and FMC which side would you remove?
 

yellowtruck29

Member
Location
Akron ohio
Occupation
inspector
Maybe thats the key word I'm not sure if I found the word single supply side bond jumper in the code book ??
Im hoping we can get some more people to chime in on this topic thanks
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Services employing metallic conduit, meter sockets, and MBJs always have some parallel paths with or without added bonding. I've not seen it addressed by the NEC but it's be an accepted provision forever.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Maybe thats the key word I'm not sure if I found the word single supply side bond jumper in the code book
You won't find it the the NEC. The requirement is to bond a metallic service raceway with something other than standard locknuts. For full size KO's that could be a single bonding locking on one end.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I am hoping to see who may have some good knowledge about parallel paths between meter socket and the 1st means of disconnect. I seen a job recently where there was a supply side bond jumper ran between the meter socket and the 1st means of disconnect with a connection to neutral at each end and bond bushing on each end with emt on one side to flex on the other side. I say this is objectional current and could be dangerous cause I'm pretty sure the neutral current will take both paths. What is some input on this ?? Thanks
Is there any online testing or information I can find to prove this ?? We seem to have some disagreement on this 🤔
The would very likely violate the rules for parallel conductors.
 
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