ICC Residential Electrical Inspectors Practice Exam

How should appliances be protected against overcurrent?

1. In accordance with the manufacturer's recommendation

2. At the discretion of the installer

3. According to the rating of the appliance and its listing

4. By using the maximum circuit breaker available

The correct answer is: According to the rating of the appliance and its listing

Appliances should be protected against overcurrent according to the rating of the appliance and its listing because this ensures that the protection devices are appropriately sized for the specific electrical demand of the appliance. Appliances are tested and certified to operate safely within certain electrical limits, and using the correct rating helps prevent overheating, potential fire hazards, and damage to the appliance. When an appliance is wired on a circuit, its continuous load should not exceed the rating of any protective devices installed, such as circuit breakers or fuses. This is typically specified by the appliance manufacturer and is outlined in the National Electrical Code (NEC) which makes sure that electrical installations are safe and reliable. Proper ratings also help in preventing nuisance tripping and ensures that the appliance can function efficiently without the risk of overcurrent. Using the manufacturer's recommendation alone may not always provide comprehensive information on protection against overcurrent since it may not take into account the electrical setup of the building. Leaving it to the discretion of the installer could result in improper protection if they are not fully aware of the appliance's specifications. On the other hand, using the maximum circuit breaker available could easily lead to inadequate protection and dangerous conditions since it may allow excessive current to flow through the appliance beyond its rated capacity.