Actually 330.3(B) includes the EGC in its requirement.
Conductor in parallel
- Thread starter Adnan Hasan
- Start date
- Status
If you follow NEC the grounding conductor has to be sized as table 250.122 max 1x400mm2 equivalent to 6000AMP.
But, asper NEC there is no EGC FROM TRnsformer to MSP..Who will correct me?!!
Is it TYPO ?
That will depend on the ampacity required. Not knowing the load or the OCPD rating, all I can tell you is to see 392.80(A)(2). Derating (adjustment factors) vary with spacing and layering.
No.
Have no idea where you got 1x400mm?, or 6000A???
Anyway, sizing and whether required depends on whether they are service conductors or feeder conductors. Regardless, metal tray is required to be bonded.
Perhaps the OP'er should clarify service or feeder...
I'm in code cycle 2011, there is no 330.3(B).
Yes, that's the max size in Table 250.122... but 4 sets of 300mm? will not have 6000A fusing or breaker. More likely 1600A or less, so looking at maybe a 125mm? copper EGC... if a feeder.
Absolutely right, i just wanted to show the max EGC that we could use is 400mm2 as 250.122 not 4x300mm2 as the OP says.
Initially i thought that service conductor is the one coming from building outside up to service conductor or the separately derived system located inside.
But now after refer to feeder definition, i just wondering what would be difference SC VS F when the separately derived system is located outside.
Aside from nuances associated with terminology and separate requirements, the essential difference is grounding.
If a feeder, it requires a grounding conductor, bonding of non-current-carrying metal parts to the grounding conductor, and bonding of the grounded conductor to the grounding conductor/system can be at or anywhere in between the source or the [first] disconnecting means... but must be the same location where the building's grounding electrode system is connected.
If a service, the same grounding of non-current-carrying metal parts is done with the grounded conductor (or bonding jumpers thereto), and bonding of the grounded conductor to the grounding system must be at the disconnecting means.
What this means for the OP is that a grounding conductor is not required to be run if these are service conductors.
Last edited:
I think That would meet the exception of 250.32(a)..
& That would meet 250.32(a)..
both of them say feeder & branch circuit, so from your opinion the service conductor could be a single circuit as the exception of 250.32(a) says.
..
Last edited:
250.32(A) is regarding "Grounding Electrode" for "Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s)." I am perplexed by your bringing grounding electrode(s) into the discussion. I thought we were only discussing required, or not, grounding conductors for the OP situation. That said, 250.32(A) does not apply to service conductors, and the exception does not apply to a feeder supplying a building.
If the OP grounding conductor is the EGC wo would meet the exception....!!!!!
I'm confused!!!
Are you sure you mean 250.32(A) Exception??? ...cause that only applies to a branch circuit.
I know it is not the real & may be it is not applicable, but just assume there is a chiller rating greater than 2000a where meets 225.30(c) or fire pump where meets 225.30(a)(1).
Okay... I'll assume. What does 250.32(A) Exception have to do with the EGC?
- Status