I couldn't find any guidelines on how to conduct IR test (Insulation Resistance) so I would like to make one specific for a 440V generator. I believe the procedure should be the same for 6.6 kV generator.

First step is lockout / tagout for the main breaker. Safety first for obvious reason.

Next is open the covers of the generator. Using a multimeter, make sure that you get zero (0) voltage across all lines.



Use a paint marker to label all wires and terminals like this.





Disconnect all wires. Again, make sure you have consistently labeled all wires and terminals.