Final answer:
The optimum insulating SF₆ gas pressure varies depending on the equipment and application, typically ranging from 100 to 150 psig at 20°C for electric power systems. The exact value is not provided in the reference data, and it is advised to consult the equipment's datasheet or manufacturer specifications for precise information.
Step-by-step explanation:
The optimum insulating SF₆ gas pressure is not specified in the question data provided. Optimum pressures can vary depending on the equipment and the application. For high-voltage circuit breakers, typical SF₆ gas pressure ranges could be anywhere from 100 to 150 psig at 20°C for electric power systems. However, these values can significantly differ based on the manufacturer and the specific equipment specifications. As the actual value sought in the question is not available in the reference data, a definitive answer cannot be provided. It is recommended to consult the equipment's datasheet, manufacturer specifications, or engineering standards for the accurate optimum insulating SF₆ gas pressure required for a particular system or application.