Multiple grounding conductors in conduit

[liverpool]

Design drawings already show 3 hots, 1 neutral, and one ground in a conduit. If conduit size is adequate, can another grounding conductor (feeding another entity) be routed in same conduit?:-?

 

[jumper]

Depends I think. What is the grounding conductor for?

300.3(B) Conductors of the Same Circuit. All conductors of
the same circuit and, where used, the grounded conductor
and all equipment grounding conductors and bonding conductors
shall be contained within the same raceway, auxiliary
gutter, cable tray, cablebus assembly, trench, cable, or
cord, unless otherwise permitted in accordance with
300.3(B)(1) through (B)(4).

 

[liverpool]

Let me try again:

Design drawings already show [3 hots, 1 neutral, and 1 ground ? all as a single multi conductor cable feeding lighting load and routed from structure 1 to 2] inside a fiber glass conduit embedded in concrete. If conduit size is adequate, can a second grounding conductor [connects two grounding bus bars from structure 1 to 2] be routed in same conduit?. Please note that lighting loads referenced above are not emergency.:-?

 

[jumper]

Okay, I am a bit confused. Nothing new.:grin:

You have a 3 phase feeder to a separate structure and you want to run an additional grounding wire.

What is the ground for? The feeder ground will already be in the disconnect. Why do you need 2 EGCs?

 

[liverpool]

Okay, I am a bit confused. Nothing new.:grin:

You have a 3 phase feeder to a separate structure and you want to run an additional grounding wire.

What is the ground for? The feeder ground will already be in the disconnect.

The 3 phase circuit has it's own EGC.

Now,
since a designer who worked on this project prior to my arrival missed a client requirement (I am not going to argue the clients requirements at this stage of the project) of connecting all bus bars together using #2/0 wires (1st and 2nd structure have busbars).

and since the ductbank has already been poured and I don’t want to tell construction that we need another conduit, I thought of using an existing conduit that does not have a lot inside of it.

Not sure if I confused you even more?

 

[jumper]

Well, I could be wrong, it happens a lot:grin:, but if:

The feeder EGC is properly sized and conduit fill is not exceeded, than I am hard pressed to find a reason that an additional ground is not allowed.

It is just a redundant safety custumer requirement and I can not fathom why it would be illegal.

The EGC bonds the busbars and the extra one does also.

I hope I am right.

 

[jusme123]

....if I understand your situation, someone forgot to run the pipe for the 2/0 'equipotential ground' that the client is using to connect all equipment grounds together, and you want to put that in with another pipe already installed in concrete. I don't see a problem with it as long as you tie that 2/0 (equipotential ground) in with the circuits equipment ground at every junction point where it is required. Dont have the code book now, but there is some code on min size of parallel conductors might be prob, what size are ckt conductors, specifically the equipment ground conductor

 

[charlie b]

Since the "extra" grounding wire is not part of a separate circuit, 300.3(B) would not come into play. I would say it is legal to do what you are describing. A waste of the client's money, perhaps, but since it is their requirement that this extra wire be installed, it is their own decision that led to a waste of their money.

 

[jusme123]

Since the "extra" grounding wire is not part of a separate circuit, 300.3(B) would not come into play. I would say it is legal to do what you are describing. A waste of the client's money, perhaps, but since it is their requirement that this extra wire be installed, it is their own decision that led to a waste of their money.

would that 2/0 'equipotential ground' have to be tied in with the other equipment ground (for the ckt conductors) where required at junction boxes and when that equipment ground is spliced?

 

[Pierre C Belarge]

See Art 225. Are there any other circuits installed to this separate Structure?

An "Equipotential" ground installed from one structure to the other???? This may be an issue. How is it terminated?

We need more info, maybe you can explain the installation a little more clearly...

 

[Dennis Alwon]

I am thinking as Pierre -- take a look at 225.30. Sounds like you may have more than one feeder going to this structure and unless it meets the 6 or so special conditions then it would be an illegal install to run that feeder out there.

 

[jumper]

I am thinking as Pierre -- take a look at 225.30. Sounds like you may have more than one feeder going to this structure and unless it meets the 6 or so special conditions then it would be an illegal install to run that feeder out there.

Aw, crapola. I thought this was a new single feed in a existing conduit to a separate building with a redundant ground.

 

[acrwc10]

Sounds like a Telco site. Lots of redundant grounding and grids.

 

[LarryFine]

I would just use a single EGC sized at the largest one needed.

 

[Jim W in Tampa]

Is this an isolated ground ?