Frederic P. Hartwell (Amherst, MA) is a working electrician, President of Hartwell Electrical Services, Inc., and has been certified by the International Association of Electrical Inspectors as a Certified Master Electrical Inspector. He is the senior member of NEC CMP 9. Mr. Hartwell is coauthor of McGraw-Hill’s American Electricians’ Handbook, 15th Edition.

Joseph F. McPartland (deceased) is an electrical contracting consultant and coauthor of McGraw-Hill’s National Electrical Code Handbook, 25th Edition.