One more question about series ratings. NEC 240.86 addresses series ratings “Selected Under Engineering Supervision in Existing Systems” and “Tested Combinations” Please refer to last week’s post and NEC 240.86 for specific application details.

Do you use “Engineered/Selected under engineering supervision” or “Tested Combinations” series ratings

– Engineered/Selected under engineering supervision
– Tested combinations
– Both
– None