Maintenance Technician Practice Test 2025 - Free Maintenance Technician Practice Questions and Prep Guide

To determine the minimal required fuse rating for the electrical system, it's essential to first calculate the total power demand of the appliances connected to the system. In this scenario, we have three appliances with their respective wattages: A at 550W, B at 770W, and C at 330W.

Adding these wattages together gives us:

550W + 770W + 330W = 1650W

Next, we convert this total power demand into a current reading using the formula:

Current (I) = Power (P) / Voltage (V)

In this case, the voltage of the system is 110V. So, we calculate the current as follows:

I = 1650W / 110V = 15A

This result indicates that the total current load drawn by the appliances is 15A. When determining the appropriate fuse rating, it's essential to choose a fuse that is slightly higher than the calculated current to accommodate any potential inrush current or fluctuations that may occur when the appliances start up.

Therefore, while a 15A fuse would meet the capacity of 15A, selecting a 20A fuse provides an adequate safety margin, ensuring that the fuse will not blow during regular