Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Is this copper wire some sort of bonding jumper? Is this required per NEC. Why would it be installed?
Jumper?
- Thread starter Alwayslearningelec
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
If there is an EGC or SSBJ within the FMC it's not required and what is shown is not code complaint. Seems to be a NYC thing to install these incorrectly.
herding_cats
Senior Member
- Location
- Kansas
- Occupation
- Mechanical Engineer
NYC codes do not consider flex connectors as qualified grounding bond. I have seen new MC connectors that bond like this. It's kind of insane if you ask me.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So are you saying you can't use flex as EGC and thus the jumper?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
NYC Article 250 is no different than the NEC with a few minor exceptions. These bonding jumpers aren't one of them. Can you cite something specific?
- Occupation
- Licensed Electrician
I've had to do bonding jumpers like that for an airport job. It was an FAA spec.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So you think they unnecessarily installed them or did because it was in spec?
As infinity pointed out, if the conduit/flex doesn't contain an EGC (or SSBJ) then the bond would be needed but it would need to be installed correctly. If the conduit/flex has a wire type EGC then the is not necessary according to the NEC. but might be required by spec.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
I doubt that the screw that is holding the connector together has been evaluated to carry the fault current associated with a bonding jumper that size. If there is an EGC within the raceway then no jumper is required around the flex.
If FMC is installed because flexibility for vibration is required after installation then an EGC is required within the raceway so the point should be moot.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So conduit service as an EGC correct? The flex would not qualify as one of no wire type one is installed within conduit?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
Take a look at 250.118 for when FMC qualifies as an EGC and when it does not. If flexibility for vibration mitigation is required for something like a transformer then the FMC does not qualify as an EGC.