Underground Installation 300.5

[Carultch]

When running Rigid Metal Conduit, 300.5 “does not” clarify if the 90 degree transition from a rigid horizontal run to vertical SCH 80 (emerging) has to be a 90 Rigid Metal Conduit or if it can be PVC?

Since it does not state anything about the 90 whatsoever when transitioning from horizontal rigid metal conduit to vertical SCH 80, I assume it can be either.

I am thinking 300.5(D)(4) gives permission for the 90 to be PVC since it mentions SCH 80.

Can the 90 be PVC, and what part of 300.5 proves this point?

If you are going to run RMC underground, why not just run RMC the full length? Or am I misunderstanding your setup?

Usually it would be PVC underground, and conservatively if needed, RMC sweeps, and RMC risers, bonded at their respective terminal enclosures.

 

[GoldDigger]

Are you talking about using a threaded PVC connector or just a slip fit?

 

[ElectroMagnetism]

Are you talking about using a threaded PVC connector or just a slip fit?

Here is the layout from posting #4:

This is a ten foot service entrance run to panel:

Splice Box > 10ft RMC underground (12 inches deep) > PVC 90 > SCH 80 vertical up > PVC expansion joint > meter can.

Where in the code does it say I cannot use a 90 to transition from the RMC to the SCH80?

Thanks

 

[GoldDigger]

Well, a lot would depend on whether you used an electrical PVC 90 or a much tighter radius plumbing PVC 90.
You do have to pull the wires.
What I was asking, basically, was whether the 90 you used was threaded on one end to fit the RMC and a glue joint on the other end for the schedule 80?

 

[kwired]

Here is the layout from posting #4:

This is a ten foot service entrance run to panel:

Splice Box > 10ft RMC underground (12 inches deep) > PVC 90 > SCH 80 vertical up > PVC expansion joint > meter can.

Where in the code does it say I cannot use a 90 to transition from the RMC to the SCH80?

Thanks

Do you have PVC on both ends or just one end?

You need to at very least bond the RMC. Only exception I am aware of for isolation of metal portions of raceway is at elbows - and they must be 24 inches deep or must be bonded.

 

[ActionDave]

......Where in the code does it say I cannot use a 90 to transition from the RMC to the SCH80?

Thanks

No where. It just says you have to bond the RMC.

 

[ptonsparky]

You actually need a fitting of some sort to transition from RMC to PVC. No one cares where you do it although the burial depth to PVC is supposed to be 18" so that may be a hitch.