514.16 Grounding and bonding

[chevyx92]

514.16 said all metal raceways need to be grounded and bonded and shall comply with 501.30.
501.30(B)(1) the locknut-bushing and double locknut types of contacts shall not be depended on for bonding purposes, but bonding jumpers with identified fittings or other approved means of bonding shall be used. My question is, can I use bonding locknuts to establish bond for conduit? Or do I have to use grounding bushings? This installation will have EMT installed inside, so I would like to use bonding locknuts at junction boxes and not grounding bushings if possible to comply with 514.16.

 

[don_resqcapt19]

Bonding locknuts are fine assuming that you have metal enclosures. Note that this bonding has to extend back the the location of the system or main bonding jumper which ever applies to the installation.

 

[augie47]

That is one Code requirement that is routinely overlooked.......................................

 

[chevyx92]

Bonding locknuts are fine assuming that you have metal enclosures. Note that this bonding has to extend back the the location of the system or main bonding jumper which ever applies to the installation.

Yes, metal junction boxes.

 

[Strathead]

That is one Code requirement that is routinely overlooked.......................................

Yeah, I didn't know it.

 

[WaveGuide]

514.16 said all metal raceways need to be grounded and bonded and shall comply with 501.30.
501.30(B)(1) the locknut-bushing and double locknut types of contacts shall not be depended on for bonding purposes, but bonding jumpers with identified fittings or other approved means of bonding shall be used. My question is, can I use bonding locknuts to establish bond for conduit? Or do I have to use grounding bushings? This installation will have EMT installed inside, so I would like to use bonding locknuts at junction boxes and not grounding bushings if possible to comply with 514.16.

I don't know for sure, but given that these sections are about wiring around Motor Fuel Dispensing Facilities, (i.e. with fumes), it would seem to me that there is the need to avoid sparks of any kind, so these extra bonding requirements for Class I locations. If not in Class I then just the nuts and metal boxes might work find.

 

[augie47]

I don't know for sure, but given that these sections are about wiring around Motor Fuel Dispensing Facilities, (i.e. with fumes), it would seem to me that there is the need to avoid sparks of any kind, so these extra bonding requirements for Class I locations. If not in Class I then just the nuts and metal boxes might work find.

Don't overlook don's reply (Post #2) "
Note that this bonding has to extend back the the location of the system or main bonding jumper which ever applies to the installation.

 

[rbalex]

The NEC doesn't necessarily explain why some of its more arcane rules exist. In this case, one has been covered reasonably well in this thread; i.e., tight bonding is necessary to avoid any arcing stray, or circulating currents that could exist and ignite an atmosphere AND to make sure that the arcing that might otherwise exist doesn't occur inside the classified location by making the strict bonding requirements apply all the way back to the source. A second, less apparent, reason is double-locknuts, or locknut-bushings connections cannot reliably meet the minimum thread count requirements of Section 500.8(E); hence, "proper fittings or other approved means of bonding" must be used.