166. For troubleshooting purposes, the key indicator to the safety and general condition of high voltage circuitry is insulation resistance. For a 6.6 kV high voltage system, what would be the recommended minimum insulation resistance value?

For a 6.6 kV high-voltage system, the recommended minimum insulation resistance is 7.6 megohms, based on the common guideline of system voltage in kV plus 1. This rule provides a benchmark for assessing insulation health and safety; always refer to manufacturer instructions and the vessel's safety management system for specific acceptance criteria.