Normas

CONTENTS

Contents
ARTICLE ARTICLE

90

Introduction ........................................ 70– 1

240

Overcurrent Protection ........................... 70– 63 I. II. III. IV. V. VI. VII. VIII. IX. General .......................................... Location ......................................... Enclosures ...................................... Disconnecting and Guarding................ Plug Fuses, Fuseholders, and Adapters .... Cartridge Fuses and Fuseholders ........... Circuit Breakers ............................... Supervised Industrial Installations .......... Overcurrent Protection Over 600 Volts, Nominal ..........................................

Chapter 1 General
100 Definitions ......................................... 70– 4 I. General.......................................... 70– 4 II. Over 600 Volts, Nominal ..................... 70– 10 110 Requirements for Electrical Installations ..... 70– 11 I. II. III. IV. General .......................................... 600 Volts, Nominal, or Less ................. Over 600 Volts, Nominal ..................... Tunnel Installations over 600 Volts, Nominal .......................................... V.Manholes and Other Electric Enclosures Intended for Personnel Entry, All Voltages. [ROP 1–240] ...........

70– 70– 70– 70– 70– 70– 70– 70–

63 66 70 70 70 71 71 72

70– 11 70– 14 70– 17 70– 20 70– 20

70– 73 70– 74 70– 77 70– 83 70– 87 70– 88 70– 70– 70– 70– 90 95 97 98

250

Grounding and Bonding ......................... 70– 74 I. General .......................................... II.System Grounding ............................ III. Grounding Electrode System and Grounding Electrode Conductor ............. IV. Enclosure, Raceway, and Service Cable Grounding ....................................... V. Bonding ......................................... VI. Equipment Grounding and Equipment Grounding Conductors ........................ VII. Methods of Equipment Grounding .........VIII. Direct-Current Systems ....................... IX. Instruments, Meters, and Relays ............ X. Grounding of Systems and Circuits of 1 kV and Over (High Voltage) ...............

Chapter 2 Wiring and Protection
200 210 Use and Identification of Grounded Conductors .......................................... 70– 23 Branch Circuits ................................... 70– 25 I. GeneralProvisions ............................ 70– 25 II. Branch-Circuit Ratings ....................... 70– 29 III. Required Outlets ............................... 70– 31 215 220 Feeders ............................................. 70– 35 Branch-Circuit, Feeder, and Service Calculations ........................................ 70– 37 I. II. III. IV. General .......................................... BranchCircuit Load Calculations .......... Feeder and Service Load Calculations ..... Optional Feeder and Service Load Calculations ..................................... V. Farm Load Calculation ...................... 280

225

Outside Branch Circuits and Feeders ......... 70– 47 I. General .......................................... 70– 47 II. More Than One Building or Other Structure......................................... 70– 50 III. Over 600 Volts ................................. 70– 52

D

A R
285

Surge Arresters .................................... 70–100

I. General .......................................... 70–100 II. Installation ...................................... 70–101 III. Connecting Surge Arresters .................. 70–101 Transient Voltage Surge Suppressors:TVSSs ............................................... 70–102

T F

70– 99

70– 37 70– 38 70– 40

70– 43 70– 46

I. General .......................................... 70–102 II. Installation ...................................... 70–102 III. Connecting Transient Voltage Surge Suppressors ...................................... 70–102

Chapter 3 Wiring Methods and Materials
Wiring...