What is the allowed duration for a load dump in pre-contingency thermal limits?

The allowed duration for a load dump in pre-contingency thermal limits is typically limited to 5 minutes. This short time frame is essential to ensure that the system remains stable and that the transmission lines and equipment do not experience lasting damage due to high temperatures caused by increased loading. A load dump is an operation that occurs when there is a sudden removal of a large load from the system, and managing this scenario within a strict time limit helps maintain overall system reliability and safety. The 5-minute duration is designed to force operators to respond quickly, ensuring that thermal limits are respected and that any necessary corrective actions can be taken promptly to prevent potential equipment failures or negative impacts on the grid. This approach reflects the importance of adhering to operational protocols in maintaining efficient and secure electricity transmission.