CHAPTER 3 GENERATORS

INTRODUCTION

As a Construction Electrician, you may have the responsibility for the installation, maintenance, and repair of electrical power generation equipment. In time of war or national emergency, Advanced Base Functional Components (ABFC) will normally be used at temporary overseas bases. Even in peacetime, generation equipment is used at remote bases or as emergency and backup power on most naval bases. A power distribution system includes all parts of an electrical system between the power source and the load. This chapter gives the correct procedures for the operation and maintenance of power plants and distribution systems and presents technical informa- tion for the selection and installation of power- generating plants.

POWER GENERATION

The characteristics built into naval electrical installations are simplicity, ruggedness, reliability, and flexibility to permit continued service. It is the function of those who operate these plants to make full use of the installation's inherent capabilities and to maintain, as far as possible, uninterrupted availability of electrical power where it is needed. To be able to do this, operating personnel should possess the following:

A thorough knowledge of how to operate and maintain the components of an electrical plant

A complete familiarity with the electrical plants distribution capabilities

An understanding of the electrical system operation of the base

The ability to apply electrical and electronic principles to specific installations

The sizing and installation of secondary conductors

EMERGENCY/STANDBY POWER

When you set up an emergency/standby power system, numerous factors must be considered. The following text will cover a few of the possible situations you may encounter. This chapter does not include the automatic transfer aspect of switching to backup power, since this task is performed by some- one with a Navy Enlisted Classification (NEC) code, CE-5601 Uninterruptible Power Supply (UPS). For our discussion in this section, we will be using the term emergency-the concepts involved are equally applicable to "standby" systems. Remember that the National Electrical Code

^® requires emergency and standby systems to be kept entirely separate from all other wiring and equipment. For more detailed information, see article 700 of the National Electrical Code

^® .

SYSTEM DESIGN

Whether you are designing and installing an emer- gency backup system or operating and maintaining an existing system, you must be completely familiar with the installation requirements and the physical charac- teristics of the equipment. The design, material, and installation must comply with electrical safety standards and codes.

In general, when emergency power is discussed, it is assumed to be replacing "normal" power. The choice of arrangement and the size and the type of equipment depend in large measure on the loads to be fed from the emergency system. The system includes all devices, wiring, raceways, transfer switch, energy source, and other electrical equipment required to supply power to selected loads. These selected loads will be determined by the available power from your emergency power source. Figures 3-1 and 3-2 show two possible arrangements for emergency/standby power hookups.

GENERATOR SELECTION

When an overseas base is first established and electrical power is required in a hurry, you will not have time to set up a centrally located generating station; instead, you will spot a portable plant at each important location requiring power. Table 3-1 lists some of the standard alternating current (ac) generators available. These standard generators are capable of meeting the power requirements of advanced bases and also those for permanent or portable emergency power.