50 Modern Commercial Wiring Copyright Goodheart-Willcox Co., Inc. subjected to these forces of nature. Building code requirements tend to be more strict for buildings designed for public use. Construction Specification Institute Figure 4-11. The CSI MasterFormat separates construction topics into broad divisions. Building codes address the types of construc- tion methods and materials that can be used. Unspecifi ed materials and methods are accept- able if they are approved by the proper author- ity. Codes will also specify specifi c materials and methods that are unacceptable for a given type of construction. Many building codes specify model codes to be followed. Model codes are extensive codes established by national organizations. The organization that establishes the model code continually researches and updates the code to incorporate new technology, materials, and methods. The model electrical code used throughout the United States is the National Electrical Code. Most local building codes require work to be performed according to this model code. The local codes may include additional require- ments in specifi c areas. M PANEL 'A' 'L1' PANEL 'P1' PANEL 'P2' PANEL 3 #4/0, 1 #6 GND 2" C 4 #4/0, 1 #6 GND 2 1/2" C 'B' PANEL 1 1/4" C 3 #2, 1 #8 GND 100/2 200A KTN-R 200/2 200A KTN-R 200/2 200A KTN-R 200/3 200A KTN-R 200/3 200A SPACE SPACE 200A G N #3/0 TO METAL PIPING PER NEC 250-50(a) PER NEC 250-50(b) #3/0 TO BLDG. METAL ELECTRODE #3/0 TO GROUND POWER CO. SECONDARY TO TRANSFORMER 4" RAISED CONC. PAD 800 AMP, 120/240V, 3Ø, 4W, NEMA 3R SERVICE ENTRANCE SECTION (S.E.S.) BRACED FOR 65,000 A.I.C. POWER CO. & U.L. APPROVALS REQUIRED Goodheart-Willcox Publisher Figure 4-10. This single-line diagram shows the conductors and equipment used to transmit power from a transformer to panels. The panels are used to feed the building loads. CSI MasterFormat Divisions Division 20 Reserved Division 21 Fire Suppression Division 22 Plumbing Division 23 Heating, Ventilating, and Air Conditioning Division 24 Reserved Division 25 Integrated Automation Division 26 Electrical Division 27 Communications Division 28 Electronic Safety and Security Division 29 Reserved