Question

$$(a)$$ What current is taken by a $$3\ kW$$ electric geyser working on $$240\ V$$ mains?

$$(b)$$ What size fuse should be used in the geyser circuit?

Answer 1

$$(a)$$ Given,

Power rating of the electrical geyser, $$P=3\ kW=3000\ W$$

Voltage supply, $$V=240\ V$$

Current, $$I$$

We know,

$$P=V\times I$$

$$\implies I=\dfrac PV$$

$$I=\dfrac{3000}{240}$$

$$I=12.5\ A$$

$$(b)$$ Current, $$I =12.5\ A \approx 13\ A$$

A $$13\ A$$ fuse should be used in the geyser circuit.