Conductor Sizing

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wmeek

Senior Member
Location
Texas
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Electrician
Can #8 THHN in a 3/4" Conduit approximatly 80' run be used to feed a 50A inlet box on a 50A Breaker . It looks like #8 is good for 50A per Table 310-16 in 75Deg column
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Make sure that the inlet is rated for 75 degrees C. Some of the ones that are available are only rated for 60 degrees C. I use the ones that have pigtails on the inlet device to avoid the issue.
 

wmeek

Senior Member
Location
Texas
Occupation
Electrician
So I checked the GE 50A Inlet box and its only rated for 60Deg conductors so i will use #6 for the Hots and neutral and a #10 for the ground. So 3-#6 at .0507 = .1521 + .0211 =.1732 which will still fit in a 3/4" Emt.
Thanks for reminding me of the rating of inlet box
 

Dennis Alwon

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Chapel Hill, NC
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Retired Electrical Contractor
So I checked the GE 50A Inlet box and its only rated for 60Deg conductors so i will use #6 for the Hots and neutral and a #10 for the ground. So 3-#6 at .0507 = .1521 + .0211 =.1732 which will still fit in a 3/4" Emt.
Thanks for reminding me of the rating of inlet box
That is why I stated if all the equipment was rated 75C. Good thing Trevor had experience with that particular device...👍
 

infinity

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Location
New Jersey
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Journeyman Electrician
The 50 amp Generac inlet I installed several years ago had only 60° C terminals. I had run #8 MC cable that was left over from a job and ended up having to install a junction box adjacent to the inlet to pigtail off the inlet with #6's. Basically this was a marine inlet in an enclosure for a generator connection. Now I only use the ones with the pigtails.
 

jap

Senior Member
Occupation
Electrician
The 50 amp Generac inlet I installed several years ago had only 60° C terminals. I had run #8 MC cable that was left over from a job and ended up having to install a junction box adjacent to the inlet to pigtail off the inlet with #6's. Basically this was a marine inlet in an enclosure for a generator connection. Now I only use the ones with the pigtails.

Funny how quickly a simple 27d F difference can ruin a perfectly professional install.

JAP>
 
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