American Electricians' Handbook, Fourteenth Edition
Filled with practical advice and facts, this definitive resource provides essential information on designing, installing, operating, and maintaining electrical systems and equipment.
TABLE OF CONTENTS American Electricians' Handbook, Fourteenth Edition
Division 4: GENERAL ELECTRICAL EQUIPMENT AND BATTERIES
INTRODUCTION
1 Introduction. In this division the miscellaneous equipment, materials, and devices which are employed for electrical installations are discussed. Certain items which are used for specific types of installations have not been included in this division; an explanation of these devices or materials will be found in Div. 8, Outside Distribution, or in Div. 9, Interior Wiring. Since there is so much material to cover for generators, motors, and transformers, a separate division (Div. 7) has been devoted to generators and motors and another (Div. 5) to transformers.
The aim in the preparation of Div. 4 has been to present the different types of equipment, materials, and devices which are available, with sufficient explanation of their characteristics, installation, and maintenance so that proper equipment can be intelligently selected, installed, and maintained in good condition for satisfactory service. Much useful information that is not ordinarily readily available at short notice has been included.
SWITCHES
2 A switch is a device for making, breaking, or changing connections in an electric circuit under the conditions of load for which it is rated. It is not designed for interruption of a circuit under short-circuit conditions. Refer to Sec. 59 for a discussion of the difference between circuit breakers and switches.
3 Switches may be classified in several different ways:
| I. | According to number of poles | 2. | Driptight | ||||
| A. | Single-pole | 3. | Weather-resisting | ||||
| B. | Two- or double-pole | 4. |
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