EGC in conduit?

Status
Not open for further replies.
M

mayjong

Senior Member
i've always thought that running a EGC from a sub to main the EGC was required to be IN the conduit (NMC used) with the feeders...
reading the requirements, i'm not so sure....
thoughts please, i'm having a rather difficult Monday...:confused:
 
Which requirements are you reading? And which code cycle? In the 2005 and earlier codes cycles sub panels in separate structures were permitted to use the grounded conductor for grounding.
 
Generally required.
300.3 Conductors.
...
(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).
Click to expand...
 
hoozonfirst said:
he said NMC- Non Metallic Conduit
Click to expand...

I have never heard nonmetallic conduit refered to as "NMC" see below for a def of NMC

334.2 Definitions.

Nonmetallic-Sheathed Cable. A factory assembly of two or more insulated conductors enclosed within an overall nonmetallic jacket.

Type NM. Insulated conductors enclosed within an overall nonmetallic jacket.

Type NMC. Insulated conductors enclosed within an overall, corrosion resistant, nonmetallic jacket
 
Read the exceptions. Exception (B)(3) fits for non-magnetic wiring methods. But you'd have to have a plastic or aluminum box where the conduit terminates. Also not sure this permits to run an EGC on the outside of a raceway though.
 
mayjong said:
i've always thought that running a EGC from a sub to main the EGC was required to be IN the conduit (NMC used) with the feeders...
reading the requirements, i'm not so sure....
thoughts please, i'm having a rather difficult Monday...:confused:
Click to expand...


I think it use to be allowed back in 96 or before. Seems like I saw a picture with it strapped to the outside of the conduit.
But your neutral had to be insolated and on the inside.

Now in 08 I'm not sure what the exceptions to allow this are.
I don't have my book with me.
 
thanks... 05 NEC , and it is not at a seperate structure. i did mean non-metallic conduit...should be RNC :(
i was looking through 300, and i just couldn't isolate the section that stated it...
 
(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).
...
(3) Nonferrous Wiring Methods. Conductors in wiring methods with a nonmetallic or other nonmagnetic sheath, where run in different raceways, auxiliary gutters, cable trays, trenches, cables, or cords, shall comply with the provisions of 300.20(B). Conductors in single-conductor Type MI cable with a nonmagnetic sheath shall comply with the provisions of 332.31. Conductors of single-conductor Type MC cable with a nonmagnetic sheath shall comply with the provisions of 330.31, 330.116, and 300.20(B).
 
don_resqcapt19 said:
...
(3) Nonferrous Wiring Methods. Conductors in wiring methods with a nonmetallic or other nonmagnetic sheath, where run in different raceways, auxiliary gutters, cable trays, trenches, cables, or cords, shall comply with the provisions of 300.20(B). ...
Click to expand...
300.3(B)(3) does not apply to this installation if all the current carrying conductors (and neutral conductor if not a CCC) are run within one raceway.
 
NEC 352.60 state's that an EGC shall be installed where required. Also, NEC 250.102(E) state's that an equipment bonding jumper can be installed outside a raceway if the length of the jumper does not exceed 6 feet.
 
erickench said:
NEC 352.60 state's that an EGC shall be installed where required. Also, NEC 250.102(E) state's that an equipment bonding jumper can be installed outside a raceway if the length of the jumper does not exceed 6 feet.
Click to expand...
I do not believe there is any EBJ in this installation... and many seem to be confused exactly what an EBJ is. The most common example in my mind is a jumper that goes "around" an expansion joint of a metallic wiring method.
 
Smart $ said:
I do not believe there is any EBJ in this installation... and many seem to be confused exactly what an EBJ is. The most common example in my mind is a jumper that goes "around" an expansion joint of a metallic wiring method.
Click to expand...

Yes but an EBJ is sized the same as an EGC. They both serve the same purpose of providing an effective fault current path.
 
erickench said:
Yes but an EBJ is sized the same as an EGC. They both serve the same purpose of providing an effective fault current path.
Click to expand...

That depends on if the equipment bonding jumper is located on the line or load side of the service or if it is located upstream from the overcurrent protective device for the secondary conductors of a separately derived system. Check out 250.30(A)(2) and 250.102(C).

Chris
 
300.5(I) requires all conductors to be in the same enclosure, raceway, cable or trench.
A bonding jumper can be on the exterior for up to 6 ft.
If you install an EGC on the outside for over 6ft the circuit impedance will be so high that the EGC may not operate the OCD in a fault condition.
 
Status
Not open for further replies.
Top