raceways

[paul renshaw]

When you install a GEC in a metal conduit, the conduit must be bonded on both ends. If you have a metal (emt) conduit run, that contains an EGC, that changes over to non-metallic flex at the end(say connection to a machine), would the conduit need to be bonded on both ends? Is there a code requirement pertaining to this? I recently have seen some installations like this and this question arose. Paul

 

[jbwhite]

Re: raceways

EGC, Equipment grounding conductor, does not often have to be bonded to the conduit at either end. sometimes it does.

You bond the EGC to the boxes not necessarily the conduit.

The GEC, grounding electrode conductor, needs to be bonded to the metal raceway at both ends.

 

[paul renshaw]

Re: raceways

You say sometimes the EGC must be bonded to the conduit. What are examples of that where it would be required. I know the GEC is bonded because if not the conduit could create a choking effect, I just wondered if it would do the same to the fault current on the EGC.

 

[augie47]

Re: raceways

take a look at 250.96, 97, 98 and 250.100 for areas which might require the bonding of raceway systems.

 

[don_resqcapt19]

Re: raceways

Paul,

I know the GEC is bonded because if not the conduit could create a choking effect, I just wondered if it would do the same to the fault current on the EGC.

With the EGC, both the supply and return conductors are in the same raceway so there is no choke effect. The choke effect occurs on the GEC because it is a single AC conductor in a ferous raceway.
Don

 

[tom baker]

Re: raceways

Also lightning is not 60hz, its a much higher frequency.