300.5 Underground Installations (H) bushing

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M.E.T

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Ferndale, WA USA
Is a bushing required in the ground if you use a threaded connector and conductors that pass through? For instance a residential meter base. The conduit is going down in the ground below the meter (conduit and a 90 degree elbow) and then the conductors pass through.
 
are you refering to a bushing that could be plastic or metal that could go on the connector after the lock ring?
what size wire is passing through?
 
Does the connector have a "bushed" throat? If not, then a bushing is required.

By conductors pass through, do you mean the wiring method changes to direct burial. If not, then 300.5(H) does not apply... but I have to assume some other section will apply, so please describe the installation completely if you want our assistance.
 
300.5

300.5

This was a discussion I had with someone that said that if you used PVC in the ground and it is not continuous piece of conduit and instead of using a bell end on pvc you used a plastic threaded adapter. Then no matter the size you will need to use a plastic bushing because it is in the ground to protect the cable. In one of Mike Holts graphics in understanding the NEC chapters 1-4 he doesn't have one.
 
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It says to protect from metal conduit fitting, having said that the last paragraph says it applies to all wiring methods and enclosures....#4 and larger.
I would think a plastic pvc connector would be ok, but thats not its purpose.
 
M.E.T said:
This was a discussion I had with someone that said that if you used PVC in the ground and it is not continuous piece of conduit and instead of using a bell end on pvc you used a plastic threaded adapter. Then no matter the size you will need to use a plastic bushing because it is in the ground to protect the cable. In one of Mike Holts graphics in understanding the NEC chapters 1-4 he doesn't have one.
Click to expand...
Can't speak for MH graphics, but the section you referred to is for transitioning from conduit to direct burial wiring methods (underground, of course). The concept is the earth may shift and the cable/conductors at the transition could be subject to a sharp corner of the conduit or fitting if not rounded or bushed. Makes no difference what size the conductors are in this application.
 
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