Which of the following does not need to be known to complete a load survey?

To understand why "Open transition or Closed transition" is the correct choice for what does not need to be known to complete a load survey, we can look at the purpose of a load survey and the specific details involved.

A load survey is primarily concerned with measuring and evaluating the electrical load characteristics and energy consumption of a facility. The purpose is typically to understand the load requirements to ensure that the electrical system can adequately support the operations or to plan for future power needs.

Knowing the frequency on which the load operates is crucial since electrical devices are designed to operate optimally at specific frequencies. Understanding voltage supplied to the load is equally important to ensure that it meets the operational requirements and safety standards of the equipment. Additionally, knowing the number of phases supplied to the facility is critical to evaluating the balance of the load across the phases, which ensures efficiency and prevents overloading.

In contrast, whether the transition is open or closed primarily pertains to how power is transferred from one source to another during switching operations and does not directly impact the basic requirements for assessing load. Thus, it is not essential to complete the load survey itself. The focus of the survey is primarily on load measurements rather than the types of transition methods for power supply, making it the least relevant choice