Determining service size by the main disconnect

Electrical · Service Boxes · printed page 89 (PDF page 90)

Book index entries

Electric Service – Determining by the Main Disconnect Service Size Determining by the Main Disconnect Electric Service – Size Service Size

Text in the illustration

check the amperage rating of the main breaker
check the amperage rating of the main fuses
note: the panel (box) rating should be no smaller than the fuses/breakers
combination panel
service box
to ground
to distribution panel
60 AMPS

Generated explanation

The illustration shows two ways to determine electrical service size by checking the amperage rating of the main disconnect. On the left, a combination panel contains a main breaker above two columns of branch-circuit breakers, with the main breaker circled for emphasis. On the right, an open service box contains two cartridge fuses marked 60 AMPS, with conductors leading to a distribution panel and a grounding connection labeled. A central note states that the panel or box rating should be no smaller than the fuse or breaker rating.

Components

combination panel main circuit breaker branch-circuit breakers service box main cartridge fuses fuse holders disconnect switch electrical conductors grounding conductor conduit

Materials

metal enclosures metal conduit insulated electrical wiring