grounding electrode conductor in pvc to rigid

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Ejones77

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spec say to use rigid ells and no exposed pvc stub ups thru slab must be rigid conduits 250.80 come in to play. can I just bond both end of the rigid and will it be ok????
 
Is your metal rigid conduit for service use? Is your metal rigid conduit bonded to an electrical panel or junction box which has an equipment ground bonded to the enclosure?
 
If you are installing rigid 90s in a PVC run for a grounding electrode conductor, I see no way to bond both ends of the rigid 90s as required in 350.64.
 
don_resqcapt19 said:
If you are installing rigid 90s in a PVC run for a grounding electrode conductor, I see no way to bond both ends of the rigid 90s as required in 350.64.
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The 90's also extend out of the ground with rigid conduit. At least that is what I thought the op stated.
 
Dennis Alwon said:
The 90's also extend out of the ground with rigid conduit. At least that is what I thought the op stated.
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That's the way I read it from the OP, "no exposed pvc stub ups". Just bond the GEC to the RMC on each end and he's good to go.
 
infinity said:
That's the way I read it from the OP, "no exposed pvc stub ups". Just bond the GEC to the RMC on each end and he's good to go.
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I'm not sure that would meet the requirement and the physics involved that the code is trying to address. Never considered this arrangement before of ferrous metallic at each end with PVS in between. One way to be sure of compliance what be to use AL 90s and just skip the bonding of the ends.
 
If the OP has PVC between the ridgid 90' how will he bond the 90's on both ends?

Roger
 
Dennis Alwon said:
Roger I believe there is a stub up with rigid pipe from the elbows.
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Even so, if both ends of every piece of RMC can not be bonded we have a choke problem. If we start with RMC and change to PVC how are you going to bond both ends of the RMC?

Roger
 
roger said:
Even so, if both ends of every piece of RMC can not be bonded we have a choke problem. If we start with RMC and change to PVC how are you going to bond both ends of the RMC?

Roger
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Didn't see it that way-- you have a point. Could an underground clamp be used on the end of the elbow? Problematic to say the least.
 
Dennis Alwon said:
Didn't see it that way-- you have a point. Could an underground clamp be used on the end of the elbow?
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If it were me I would ignore the spec in this case and use PVC for the entire sleeve.

Roger
 
You could use PVC coated aluminum rigid conduit, or provide a protective barrier between concrete and non-coated aluminum conduit. Bonding on both ends would not be required because aluminum does not noticeably increase the inductance of the GEC path.
 
synchro said:
If the concern is just for protection then you could sleeve PVC conduit stubs with a section of larger diameter RMC.
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Sleeving RMC around the PVC still leaves a choke issue the same as a metallic mineral strap around the PVC would do.
Either use PVC or RMC one or the other and be done with it. I would still opt for PVC.

Roger
 
roger said:
Sleeving RMC around the PVC still leaves a choke issue the same as a metallic mineral strap around the PVC would do.
Either use PVC or RMC one or the other and be done with it. I would still opt for PVC.

Roger
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You must have caught this just a minute after I posted this because I removed it while I could still edit it. You could still sleeve it as long as it wasn't ferrous RMC.
 
Sounds to me like you are not even permitted to mix ferrous and non-ferrous raceways when used with a GEC.

250.64(E) Raceways and Enclosures for Grounding Electrode Conductors.
(1) General. Ferrous metal raceways and enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. Ferrous metal raceways and enclosures shall be bonded at each end of the raceway or enclosure to the grounding electrode or grounding electrode conductor to create an electrically parallel path. Nonferrous metal raceways and enclosures shall not be required to be electrically continuous.
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The requirement for RMC is, IMO, ridiculous. This raceway is for the grounding electrode conductor. Why does it need to be rmc. Install schedule 80 PVC where it comes up.

I would ask the powers to be if that would be okay or ask them how you are to bond both ends.
 
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