According to IEEE 841, unless otherwise specified, all electrical performance tests shall be conducted in...

The correct answer isB, IEEE Std 112. IEEE 841 applies to severe-duty, totally enclosed squirrel-cage induction motors used in petroleum and chemical industry service, and when it refers toelectrical performance testing, the standard points toIEEE Std 112as the governing test method unless the purchase specification states otherwise. IEEE Std 112 is the recognized standard for defining methods to determine motor performance characteristics such as efficiency, losses, current, power factor, and related operating behavior during testing.

The other options are not the best answer for this question.NEMA MG-1is a broad motor standard covering design, construction, and application requirements, but it is not the primary referenced document for conducting electrical performance tests in this context.IEEE Std 117relates more to test procedures and acceptance considerations for certain motor categories, but not the default performance-test basis cited here.IEEE Std 522is associated with insulation testing of form-wound stator coils and windings, not overall motor electrical performance testing.

Therefore, for source inspection of large electric motors, the correct referenced performance-test standard isIEEE Std 112.