How many conductors are contained in each conduit in the 210.10 example?

How many conductors are contained in each conduit in the 210.10 example?

• A. eight
• B. two
• C. six
• D. four

Answer: (D)

Conduit fill is about how many conductors can share a raceway based on their size. For counting toward that fill, every current-carrying conductor inside the conduit is counted one by one. Equipment grounding conductors are treated specially: all grounding conductors together count as a single conductor for fill, regardless of how many there are. In the 210.10 example, each conduit has two current-carrying conductors (the two hot/ungrounded wires) plus one grounded conductor (the neutral). There are also grounding conductors present, but all of them collectively count as one conductor. So the total in each conduit is two (hots) + one (neutral) + one (grounding conductors counted as one) = four conductors.

Conduit fill is about how many conductors can share a raceway based on their size. For counting toward that fill, every current-carrying conductor inside the conduit is counted one by one. Equipment grounding conductors are treated specially: all grounding conductors together count as a single conductor for fill, regardless of how many there are.

In the 210.10 example, each conduit has two current-carrying conductors (the two hot/ungrounded wires) plus one grounded conductor (the neutral). There are also grounding conductors present, but all of them collectively count as one conductor. So the total in each conduit is two (hots) + one (neutral) + one (grounding conductors counted as one) = four conductors.