Running equipment grounding conductor outside raceways.
Running equipment grounding conductor outside raceways.
(OP)
thread238-248237: Routing feeder equipment grounding conductor OUTSIDE of conduit?
A previous thread on this subject has been closed, but the question was not answered correctly.
The O.P. had asked if it was ok to run the EGC on the outside of an existing cable, in an existing installation.
The thread ended when someone posted the text of NEC code section 300.3(B), which stated that you can not run an EGC outside of the raceway carrying the circuit conductors.
However, in the O.P.'s case, an EXISTING INSTALLATION, 300.3(B)(2) states "Euipment Grounding conductors shall be permitted to be installed outside a raceway or cable assembly where in accordance with the provisions of 250.130(C) for certain EXISTING INSTALLATIONS".
I believe the wording includes "CERTAIN existing installations" so an AHJ or inspector may still refuse to accept such an install. But, in a case where existing cables are to be used for a new purpose(such as for temporary power), it may be deemed more practical to run an external EGC than pull an entirely new cable, and this section of the code provides a solution for such corcumstances.
A previous thread on this subject has been closed, but the question was not answered correctly.
The O.P. had asked if it was ok to run the EGC on the outside of an existing cable, in an existing installation.
The thread ended when someone posted the text of NEC code section 300.3(B), which stated that you can not run an EGC outside of the raceway carrying the circuit conductors.
However, in the O.P.'s case, an EXISTING INSTALLATION, 300.3(B)(2) states "Euipment Grounding conductors shall be permitted to be installed outside a raceway or cable assembly where in accordance with the provisions of 250.130(C) for certain EXISTING INSTALLATIONS".
I believe the wording includes "CERTAIN existing installations" so an AHJ or inspector may still refuse to accept such an install. But, in a case where existing cables are to be used for a new purpose(such as for temporary power), it may be deemed more practical to run an external EGC than pull an entirely new cable, and this section of the code provides a solution for such corcumstances.






RE: Running equipment grounding conductor outside raceways.
At one time, steel armoured cables were common. Now cable armour is almost exclusively aluminum. There is less technical reason to have the grounding conductor enclosed in the non-magnetic armour.
You should only consider running a separate grounding conductor outside of non-magnetic armoured cables.
In the case of steel raceways the ground conductor must always be within the same magnetic enclosure as the power conductors. For parallel runs in more than one steel raceway best practice is to include a grounding conductor in each raceway.
As of 2015, the Canadian code requires parallel bonding conductors foe parallel runs.
I realize that this doesn't answer your question directly but knowing the reason behind the rule may help.
Check with your local AHJ for a ruling.
Bill
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"Why not the best?"
Jimmy Carter
RE: Running equipment grounding conductor outside raceways.
Note that if the existing circuit was installed using a wiring method that does not have an outer ferrous covering, then 300.3(B)(3) would permit the external EGC run with the circuit conductors.