Conduit accepted as ground.

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Mark Horner

terminator
Location
Orange,va. USA
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industrial electrician
NEC says that conduit can be used as the ground,I`m not sure sure how this could be at all acceptable due to the vulnerability of the connection that is easily susceptible to being disrupted,can someone explain to me about this?
 
Properly installed metallic raceways can continue to serve as a solid grounding conductor for decades.

Sloppily installed metallic raceways; meh... not to reliable.

So go to 110.3(b) and 110.12(B) and you have your answer.
 
Check out NEC 300.6 -7 8-9-10-12 Those areas. Other than that and above mentioned you're getting in to "what if's" and that can go on forever.
 
The NEC is a litigation based document. Meaning there need to be enough documented cases of a latent hazard playing out to actually sway voting for a proposal. Money under the table aside.

Yes conduit connections can become loose, but it tends to be masked by all the parallel metallic paths in many commercial buildings.
 
LarryFine said:
The size of conduit needed to enclose a given set of conductors has a lower impedance than the grounding conductor that would otherwise be used with them.
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Just the way we do it. Conduit just isn't acceptable here. In fact we hardly use any conduit. The odd straight length for am appliance socket (switch) and that is invariably PVC, not EMT.
 
Besoeker3 said:
Just the way we do it. Conduit just isn't acceptable here. In fact we hardly use any conduit. The odd straight length for am appliance socket (switch) and that is invariably PVC, not EMT.
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My gripe is when you run the CPC separate from the SWA or trunking. Reactance goes way up when you do that and I hear R1+R2 not taking it into account all to often. But I digress :)
 
mbrooke said:
My gripe is when you run the CPC separate from the SWA or trunking. Reactance goes way up when you do that and I hear R1+R2 not taking it into account all to often. But I digress :)
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Remind me about CPC?
 
Mark Horner said:
NEC says that conduit can be used as the ground,I`m not sure sure how this could be at all acceptable due to the vulnerability of the connection that is easily susceptible to being disrupted,can someone explain to me about this?
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You can certainly put in a proposal to require a wire type EGC in a metal raceway, your proposal (or PI) would be for the 2026 NEC, plenty of time to gather documentation. Past proposals to require wire type EGC have been rejected with the comment that properly installed RMC, EMT, IMC is an acceptable EGC, Keep in mind who is on the CMP, take a look at CMP No. 8.
 
Mark Horner said:
corrosion between couplings or connectors or even loose locknuts
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For corrosion, section 300,6 directly addresses this. Loose locknuts is an installation issue.
The NEC is a minimum standard.
I recognize and agree with what you are saying, and I most of the time would install an wire type EGC.
Again look at the CMP for panel 8.
 
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480sparky said:
Properly installed metallic raceways can continue to serve as a solid grounding conductor for decades.

Sloppily installed metallic raceways; meh... not to reliable.

So go to 110.3(b) and 110.12(B) and you have your answer.
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my point exactly,even properly installed could corode as well.
 
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