What is the demand factor in an electrical system?

The demand factor in an electrical system is defined as the ratio of maximum demand to total connected load. This concept is crucial for understanding how much of the connected load is typically used at any given moment, rather than assuming that all connected loads will be used simultaneously.

The maximum demand represents the highest level of electrical demand observed over a specific time period, while the total connected load is the sum of all power ratings of the devices that could potentially draw power in the system. By calculating the demand factor, engineers can more accurately size equipment, such as transformers and generators, and design the electrical system to handle usual operational conditions without overbuilding for unlikely peak demands.

This understanding helps in essential tasks like load calculations, which ensure that systems are efficient and reliable. In contrast, the total connected load represents the maximum possible load but doesn't provide insight into actual usage patterns, while the other options pertain to different aspects of load and power management that don't directly define the demand factor.