A box with four internal cable clamps adds how many additional conductors to the fill allowance?

The correct answer is based on the National Electrical Code (NEC) requirements regarding the fill calculations for boxes. According to these regulations, each internal clamp within a box is counted toward the fill calculation because it occupies space and impacts the overall volume allowance within the box.

When a box has internal cable clamps, each clamp is considered to add one additional conductor to the fill allowance. This means that if a box contains four internal cable clamps, it adds four to the total count of conductors that can be accommodated within the box. However, since the question specifically states the additional conductors added to the fill allowance, it recognizes that these four clamps would effectively count as four additional conductors. In a typical scenario regarding specific fill allowances, it is commonly interpreted that each clamp can be regarded as an individual conductor in terms of box fill.

In summary, for a box with four internal cable clamps, it effectively introduces four additional conductors to the fill allowance, but if viewed as needing to select a singular numeral reflecting this addition, the typical answer expected in practical scenarios highlights additional calculation nuances often resulting in a clarification leading to a lesser count indicating a single conductor consideration due to the context of internal mechanics.