What is the minimum size wire required for a 9.5 kW heat strip on a 240-volt line?

To determine the minimum size wire required for a 9.5 kW heat strip on a 240-volt line, it's important to calculate the current that will flow through the wire. The current (in amperes) can be calculated using the formula:

[ \text{Current} (I) = \frac{\text{Power} (P)}{\text{Voltage} (V)} ]

In this case, using the given values:

[ I = \frac{9500 \text{ W}}{240 \text{ V}} \approx 39.58 \text{ A} ]

When selecting a wire size, the National Electrical Code (NEC) provides guidelines to ensure safety and efficiency. It is important to consider not only the current but also factors such as ambient temperature, installation conditions, and the wire’s insulation rating.

For a continuous load, the NEC recommends sizing wires at 125% of the load current. Thus:

[ \text{Minimum size for continuous load} = 39.58 \text{ A} \times 1.25 \approx 49.475 \text{ A} ]

Referring to the NEC's guidelines, #8 wire is rated for a maximum of