When maintenance is required at a substation, what voltage variation does it typically provide?

When maintenance is required at a substation, the typical voltage variation allowed is generally within a range of 5% above and below the nominal voltage. This means that the system can operate at voltages that are as much as 5% greater or 5% less than the nominal voltage. This range is established to ensure that equipment can function properly without risking damage from excessive or insufficient voltage levels.

Maintaining voltages within this variation is important for system reliability and efficiency, as it accommodates fluctuations due to load changes or generation variations during maintenance activities. The 5% range is common practice in the industry to balance operational needs and equipment safety, allowing for operational flexibility while ensuring the stability of the electrical grid.