Refer to 314.28(A).
Among other things, this tells you to choose between requirements 1 and 3 and,
if not a straight pull, also apply requirement 2. The fact this is a 90 degree
angle means it's not a straight pull. So you must also apply requirement 2.
However, this requirement has nothing to do with the box size.
If that raceway has only those three conductors, then you can calculate the box
size per requirement 3. But doing so means you permanently limit the box
capacity to something less than the raceway would allow. You make it a special
case, and that could be confusing for people if there's ever a need for
expansion. It can also be costly to expand, as you'd need to replace the box and
perhaps pull all new conductors.
Requirement 1 means you match the box size to the raceway size. From an
engineering standpoint, this is the preferred option unless there is a
compelling reason to go with requirement three.
The length of the box must be at least 8 times the metric designator (trade
size) of the largest raceway. If that 2-inch EMT is the largest raceway, then
you need to find out what its metric designator is. But there's no reference
anywhere near 314.28 to point you to a table showing this. However, we know that
Chapter 9 is full of tables. In fact, the word "Tables" is its title.
Fortunately, Table 4 is very close to the front of Chapter 9 so we find it right
away. It's this table that will tell you the metric designator for a given
wiring method. This table is broken out by wiring method, shown in Chapter Three
Article order. EMT (Article 358) happens to be the first one. The number you
need is 53.
Now, multiply 53 by 8, and you have the minimum length of that box: 424 mm,
which is 16.7 inches.
to be cabled or racked up in an approved manner [314.28(B).
the box must be at least 1650 sq cm (100 sq in), and you must meet the
conditions of 314.28(E)(1)-(5).
It has to
be accessible without removing any part of the building. In underground
circuits, a similar concept applies; it must be accessible without tearing up
sidewalks, digging up finished grade, etc. [314.29].
Yes, but in
such a case they must be lined with a firmly attached insulating material that's
at least 1/32 in thick and be listed for the purpose [314.41].