Oklahoma Electrical Practice Exam

For what situation is the feeder demand factor for elevators applicable?

1. For individual elevators

2. For escalators

3. For multiple elevators served by the same feeder

4. For freight elevators only

The correct answer is: For multiple elevators served by the same feeder

The feeder demand factor for elevators is particularly applicable in situations involving multiple elevators served by the same feeder. This is because when elevators are used in a building, not all elevators operate simultaneously, particularly during peak usage times when demand for elevator service is highest. The demand factor allows for a more efficient calculation of electrical load by recognizing that, statistically, only a certain percentage of these elevators will be in use at the same time. When multiple elevators share a feeder, applying the feeder demand factor can help determine the necessary capacity of the feeder, which can lead to cost savings in both the infrastructure and installation of electrical systems. This is in contrast to calculating the demand for each elevator individually, which would typically overestimate the load and result in a larger and more expensive feeder than necessary. Thus, using the feeder demand factor is essential for optimizing the electrical design for multiple elevators, ensuring safe and efficient operation while also being cost-effective.