Table 3-1.—Types of Portable GeneratorsAlternating currentFrequencyVoltage120/20812060-hertz120/208240/416Phase1l & 33Wires24*4FuelGDGDGDkW Rating5XXXX10XX15XX30XXX60X100XX200XG—Gasoline driven. D—Diesel driven.*—Panel connections permit, at rated kW output: 120/208V3-phase 4-wire, 120V 3-phase 3-wire, 120V single-phase2-wire, 120/240V single-phase 3 wire.Before any part of the system can be designed, theamount of power to be transmitted, or the electricalload, must be determined. Electrical loads are generallymeasured in terms of amperes. kilowatts, orkilovoltamperes. In general, electrical loads areseldom constant for any appreciable time, but fluctuateconstantly. In calculating the electrical load, you mustdetermine the connected load first. The connected loadis the sum of the rated capacities of all electricalappliances, lamps, motors, and so on, connected to thewiring of the system. The maximum demand load is thegreatest value of all connected loads that are inoperation over a specified period of time. Knowledgeof the maximum demand of groups of loads is of greatimportance: because it is the group maximum demandthat determines the size of generators, conductors, andapparatus throughout the electrical system.The ratio between the actual maximum demandand the connected load is called the DEMANDFACTOR. If a group of loads were all connected to thesupply source and drew their rated loads at the sametime, the demand factor would be 1.00. There are twomain reasons why the demand factor is usually lessthan 1.00. First, all load devices are seldom in use atthe same time and, even if they are, they will seldomreach maximum demand at the same time. Second,some load devices are usually slightly larger than theminimum size needed and normally draw less thantheir rated load. Since the maximum demand is one ofthe factors determining the size of conductors, it isimportant that the demand factor be established asclosely as possible.3-3