Junction Box Ratings versus minimum wire size?

[BigMotorGuy]

I have a given junction box that has a current rating above the rating of the load (induction motor). The box stated a minimum wire size which ties into the box current rating. Since the load is much lower than the box rating (e.g. 250 amp box rating for a 100 amp FLA motor rating), do I still need to have the box noted minimum wire size even though my load is rated much lower? The current wire (smaller than the box noted minimum wire size) is size appropriately for the load rating....is this unacceptable in regards to NEC or any other standards?

 

[waross]

The box doesn't care.
However, if you are concerned with the ratings of a terminal strip inside the box there is an issue.
It is common for terminal strips to be rated for wire size.
The maximum size is the largest size that will physically fit in the terminal.
The minimum size is the smallest wire that will be securely held by the terminal.
Too small wires may be connected by pigtailing a short length of a larger wire. Depending on space availability, the pigtail connections may be made in the terminal box or may have to be made in a second nearby added junction box.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[BigMotorGuy]

Thanks for the comments Warros. I get what you are saying about the physical fit, but that is not the problem. the problem is an inspector is having a problem with the wire being smaller than the minimum size noted on the box. We use hazardous area glands sized appropriately for the present smaller wire size and we use lugs which attach to standoff studs, so the physical fit is ok. My argument is that the wire size is based on the rated load and not the JB rating, so we can use a smaller wire than noted on the JB. The JB minimum wire size note is only based on full current rating of the box, but since we are only using a % of the box rating, having the smaller wire is not a reason to reject the design/install....am I wrong here?