What is the ampacity of rubber-insulated 8 AWG wire when operated at a temperature of 25 degrees C?

The ampacity of rubber-insulated 8 AWG wire at a temperature of 25 degrees Celsius is typically around 40 to 50 amperes, depending on the specific application, installation conditions, and applicable electrical codes. It's important to consult the National Electrical Code (NEC) or manufacturer specifications for precise ratings, as factors like bundling, ambient temperature, and insulation type can affect ampacity. Always ensure to consider safety margins and local regulations when determining the appropriate ampacity for your specific installation.