What is the voltage drop on a 240-volt single-phase branch circuit supplying a 100-ampere load at 105 feet using 1 AWG THWN aluminum conductors?

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To determine the voltage drop in a circuit, we can use the formula:

[ \text{Voltage Drop (V)} = \frac{2 \times K \times I \times L}{1000} ]

Where:

( K ) is the resistivity coefficient of the conductor material (for aluminum, it's typically around 12.9 ohm-mil/foot),
( I ) is the current in amperes,
( L ) is the one-way length of the conductor in feet,
The factor of 2 accounts for the round trip of the current (to and from the load).

For this particular case:

The resistivity for 1 AWG aluminum conductors is approximately 0.1267 ohms per 1000 feet.

Plugging the values into the formula:

Determine ( K ) for 1 AWG aluminum as 12.9 ohm-mil/foot.
The current ( I ) is 100 amperes.
The one-way distance ( L ) is 105 feet (we multiply this by 2 for the round trip, resulting in 210 feet in total).

Now, calculating the voltage drop:

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