Question 1

How do I calculate my home electrical load?

Accepted Answer

Add up the wattage of all appliances running simultaneously. Divide total watts by 1000 to get kilowatts. Multiply by hours used per day to get kWh consumption.

Question 2

What size circuit breaker do I need?

Accepted Answer

Multiply your load amps by 1.25 for the minimum breaker size. A 20-amp circuit needs a 25-amp breaker minimum. Always round up to the next standard breaker size.

Question 3

What wire gauge do I need for a 20 amp circuit?

Accepted Answer

A 20-amp circuit requires 12 AWG copper wire minimum. For runs over 50 feet, use 10 AWG to prevent voltage drop.

Question 4

How do I calculate voltage drop?

Accepted Answer

Voltage drop = (2 x wire length x current x resistance per foot). Keep voltage drop under 3% for branch circuits and under 5% total for feeders and branch circuits combined.

Question 5

What is Ohm's Law?

Accepted Answer

Ohm's Law states that Voltage = Current x Resistance (V = I x R). Use it to calculate any unknown electrical value when two values are known.

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