A homeowner is installing a swimming pool. You have been asked to install a circuit...

The loads in the circuit are continuous duty, so the circuit can be loaded to only \(80 \%\) of its current rating.

Calculate the \(80 \%\) current rating of the circuit breaker.

$$ \begin{aligned} I_{\mathrm{CB}} &=\left(\frac{80}{100}\right)(20 \mathrm{~A}) \\ &=(0.8)(20 \mathrm{~A}) \\ &=16 \mathrm{~A} \end{aligned} $$

Assume the value of supply voltage as \(120 \mathrm{~V}\).

Calculate the current flows through under water light (load 1).

$$ \begin{aligned} I_{1} &=\frac{500 \mathrm{~W}}{120 \mathrm{~V}} \\ &=4.167 \mathrm{~A} \end{aligned} $$

The current through the circulating pump (Load 2 ) is \(8.5 \mathrm{~A}\).

Calculate the total current in the circuit.

$$ \begin{aligned} I &=I_{1}+I_{2} \\ &=4.167 \mathrm{~A}+8.5 \mathrm{~A} \\ &=12.67 \mathrm{~A} \end{aligned} $$

The total current in the circuit obtained which is less than the circuit breaker rating current.

Therefore, the power can be operated for both the loads.