electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
How come an EGC run with parallel runs for a feeder needs to be full size in each pipe , but we don't need full size in each pipe for the SSBJ on a SDS?
SSBJ vs EGC for parallel runs
- Thread starter electrofelon
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Great question, I have no idea. IMO the SSBJ rule should apply to all parallel runs even when using an EGC.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Ok, so I'm not missing any sound electrical theory reason, such as in an SDS the electrons are more fresh and thus less likely to misbehave?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
LOL! Yeah the EGC gets me. I can use a metal raceway as an EGC but as soon as I stick a wire type EGC in there it must be full sized in each parallel raceway.
- Location
- Logan, Utah
You may get your wish.
There are several Public Inputs that have been submitted for the 2020 NEC that would radically change Table 250.122. The Public Inputs would change the table from basing the size of the EGC on the OCPD to sizing the EGC based on the size of the ungrounded conductors similar to Table 250.102(C).
I have a couple of friends on CMP 5 and this idea has some backing. It will be interesting to see where the PI goes in a few weeks at the First Draft Meeting in January.
Chris
- Location
- New Jersey
- Occupation
- Journeyman Electrician
That's good news. I believe that our moderator Don has submitted several proposals across many code cycles to do just that, base the EGC on the size of the conductors, but each time he was rejected.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
That would be nice. But note sizing based on the area of the ungrounded conductors is different than requiring a full sized in each raceway. Does the discussion for the change encompass the latter too?
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