lowlandman
Member
- Location
- Charleston, SC
I am installing a 4 wire system in a commercial warehouse with 3/0 copper feeders at 100 feet. What is code recommended ground wire size.
derating the ground in a commercial 200 amp service
- Thread starter lowlandman
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- New Jersey
- Occupation
- Journeyman Electrician
What do you mean by ground wire? There is no EGC on the line side of the service disconnect.
lowlandman
Member
- Location
- Charleston, SC
sorry, I am installing a 200 amp disconnect at meter base then 105' of 3/0 wire to new 200 amp main lug panel. I am just trying to confirm the ground wire size I need to run in conduit to new panel.
thanks
thanks
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Ah OK so you have a feeder, you would side the EGC from Table 250.122, for 200 amps with #3/0 that would be a #6 copper conductor.
"Ground" is a term that can cause you a lot of misunderstanding. To the NEC,m "Ground" is Earth.
In your situation the equipment grounding conductor and the grounded (neutral) conductor would likely not be sized the same so terminology is important.
From the title of the thread you might be sizing the neutral (grounded) conductor. If so, refer to Art 220.61 and Art 215.2
For the EGC, Art 250.122 as Infinity notes.
In your situation the equipment grounding conductor and the grounded (neutral) conductor would likely not be sized the same so terminology is important.
From the title of the thread you might be sizing the neutral (grounded) conductor. If so, refer to Art 220.61 and Art 215.2
For the EGC, Art 250.122 as Infinity notes.
lowlandman
Member
- Location
- Charleston, SC
thanks. I found chart and will bookmark
kwired
Electron manager
- Location
- NE Nebraska
Presuming you want to know what minimum size of "equipment grounding conductor" is needed, as mentioned table 250.122.
Also keep in mind if you are using metal raceway, the raceway itself does qualify as an equipment grounding conductor, but if you still decide to pull a "wire type" EGC it still needs sized by 250.122.
The grounded (neutral) conductor in this feeder can be sized to the actual maximum unbalanced load connected to it, but also can not be smaller then the values in table 250.122 - so if you had a calculated neutral load of 30 amps you still would need a 6 AWG minimum neutral conductor on a 200 amp feeder.
Also keep in mind if you are using metal raceway, the raceway itself does qualify as an equipment grounding conductor, but if you still decide to pull a "wire type" EGC it still needs sized by 250.122.
The grounded (neutral) conductor in this feeder can be sized to the actual maximum unbalanced load connected to it, but also can not be smaller then the values in table 250.122 - so if you had a calculated neutral load of 30 amps you still would need a 6 AWG minimum neutral conductor on a 200 amp feeder.
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