How Many 2/0 THHN Conductors Can I Run Through a 2 Inch LB?
A user asked the app how many 2/0 copper THHN conductors fit through a 2 inch LB. The rule that governs is NEC 2023 Section 314.16(C)(1): a conduit body can contain the same number of conductors permitted in the raceway it is attached to. So the LB itself is not the limit; the 2 inch conduit is, and the answer for 2 inch EMT is six 2/0 THHN conductors.
The fill math
Chapter 9 Table 5 lists 2/0 THHN at 0.2223 square inches per conductor. Table 4 gives 2 inch EMT a total internal area of 3.356 square inches, with 40 percent fill for three or more conductors equal to 1.342 square inches. Divide 1.342 by 0.2223 and you get 6.04, which truncates to six conductors. If the run is 2 inch rigid metal conduit the numbers land in the same place: 40 percent of RMC's 3.408 square inches is 1.363, still six conductors. Schedule 40 PVC is slightly tighter at 1.316 square inches, which also yields five point nine, so PVC caps at five. Know which raceway you are actually attached to before you count.
Note that a typical service or feeder pull of two hots, a neutral, and a ground in 2/0 and smaller passes easily; the six conductor ceiling matters on parallel runs or multi circuit pulls. Also verify the equipment grounding conductor at its own area if it is a different size, since fill is computed from the sum of all conductor areas against the 40 percent number, not from a per wire count when sizes are mixed.
LB specific rules that still apply
Two more requirements bite on conduit bodies. First, splices are only permitted in a conduit body that is durably marked with its cubic inch capacity and sized under the 314.16(B) volume rules; for straight pulls of 2/0 with no splices, the marking question does not come up. Second, Section 314.28(A)(2) requires conduit bodies containing conductors 4 AWG or larger to have a distance of at least six times the trade size between the entry and the opposite wall for angle pulls. Manufacturers build listed LBs to satisfy this for their marked size, which is one reason you buy the LB matched to the conduit instead of bushing down. Pulling 2/0 around the tight interior radius of an LB is hard on insulation, so use plenty of lubricant and feed from the cover side.