Question

What fuse rating would you choose for

(a) A heater of $1KW$ and

(b) An oven of $1500W$ , if the voltage supplied by the main is$220volt$?

Answer 1

(a)

Step 1: Given data

Power of heater, $P_1=1KW=1000W$

Power of oven, $P_2=1500W$

Supply voltage, $V=220V$

Step 2: Calculating the current that will flow through the heater($I_1$),

We know that, $Current\left(I_1\right)=\frac{Power\left(P_1\right)}{Voltage\left(V\right)}$

$I_1=\frac{P_1}{V}=\frac{1000W}{220V}=4.54A$

So, a fuse of $5A$can be used.

(b)

Step 3: Calculating the current that will flow through the oven($I_2$),

Again calculating current, $I_2=\frac{P_2}{V}=\frac{1500}{220}=6.8A$

So, a fuse of $7A$can be used in the case of an oven.