TABLE OF CONTENTS Electric service is defined as the conductors and equipment that deliver electrical power from the electric power utility's distribution system to the customers being served. The service entrance is the interface between the overhead or underground cable from the local transformer where the power utility's responsibility ends and the home or building owner's electrical system and responsibility begin. The utility splices the power cable to the owner's service entrance cable but retains ownership of the watthour meter.
This chapter also covers main service panels (a.k.a., panelboards or loadcenters) and the types of circuit breakers and fuses used to protect branch circuits in homes and offices. It explains the organization of a National Electrical Code (NEC)-approved grounding system, and discusses some of the test procedures required to assure that the ground system is performing effectively. Finally, the assemblies of cable, meter, disconnect, and fittings used for temporary service by builders and electrical contractors are illustrated and explained. At the end of the chapter is a glossary of electrical service terms for quick reference.
In overhead or aerial service, illustrated in Fig. 5-1, the high voltage from an overhead (typically) single-phase secondary line attached to a utility pole is transformed to useful values by a pole-mounted overhead transformer near the building being served. The transformer steps the single-phase power, typically at 3 to 8 kV, to 120/240 V AC. The other elements of an overhead system are the service drop
