ICC Residential Electrical Inspectors Practice Exam

The NEC states that the maximum circuit rating allowed for a non-fastened appliance on a 15 Amp circuit is what percentage?

1. 100%

2. 80%

3. 75%

4. 90%

The correct answer is: 80%

The National Electrical Code (NEC) stipulates that non-fastened appliances plugged into a 15 Amp circuit should not exceed 80% of the circuit's total rating. This limitation is put in place to ensure safety and prevent overloads that could lead to tripping circuit breakers or even electrical fires. In practical terms, since a 15 Amp circuit can handle a maximum load of 15 Amperes, applying the 80% rule means that the maximum load permitted for a non-fastened appliance would be 12 Amperes (0.80 x 15 Amperes). This offers a buffer to accommodate inrush currents or other temporary loads that could spike when the appliance is initially powered on, thereby reducing the risk of exceeding safe amperage levels during everyday use. Understanding this code provision is vital for ensuring compliance and safeguarding the integrity of electrical installations, particularly in residential settings where appliances frequently draw varying amounts of current.