See the actual nec text at nfpa org for the complete code section.
Auxiliary gutters nec.
Articles 376 and 378 focus on wireways not auxiliary gutters.
Figuring the 20 is easy for example.
The term gutter is used in this non raceway location in the nec.
Nec 110 12 a unused openings.
Article 366 auxiliary gutters i.
There are two 4inch conduits feeding the bottom of the gutter with 4x600mcm conductors in parallel in each which pass straight through to the two 4inch nipples which connect to the bottom of the meter assembly feeding the 800 amp breaker.
Sizing a gutter for the proper fit is relatively easy.
Listen as paul abernathy talks about the requirements for not exceeding 20 fill for wireways and auxillary gutters.
Unused cable or raceway openings in boxes raceways auxiliary gutters cabinets cutout boxes meter socket enclosures equipement cases or housings shall be effectively closed to afford protection substantially equivelant to the wall of the equipment if they are not going to use it.
I get a lot of calls to make sure that the gutter that they are using is up to code.
Metallic wireway selection reference nfpa 70 national electrical code 2.
Articles 386 and 388.
Nowhere 30 ft is the maximum length for any auxiliary gutter.
Most auxiliary gutters are made of ferrous metal therefore it only makes sense to keep parallel conductors grouped properly behind the gutter box cover.
This auxiliary gutter used as a pull box is 5ft long 14inches deep by 14inches in height.
Of its interior cross sectional area 366 22 a b this is for both sheet metal and nonmetallic gutters.
Where in the nec is it permitted to install an auxiliary gutter in a length longer than 30 ft.
In hazardous classified locations as permitted by nec articles 501 502 and 504.
We are allowed by code to fill a gutter to 20.
Below is a preview of article 366.
The openings must be closed.
Once there click on.
In concealed spaces as permitted in nec section 376 10.
Articles 376 and 378.
