How do you calculate the cable size by comparing load Amperes?

To calculate the appropriate cable size based on load amperes, first determine the total load current using the formula ( I = \frac{P}{V \times \text{PF}} ), where ( I ) is the current in amperes, ( P ) is the power in watts, ( V ) is the voltage, and PF is the power factor. Next, consult the cable sizing tables provided by standards such as the National Electrical Code (NEC) or the International Electrotechnical Commission (IEC), which indicate the ampacity of different cable sizes based on the calculated load current. Finally, consider factors like installation conditions, temperature ratings, and length of the cable run to select the appropriate size, ensuring a safe and efficient electrical system.