North Star 2900 Load Application, 120V, 60 Hz Motors, Current/Power Maximum Extension Cord Length

sufficient amounts must be brought in and exhausted out to ensure proper cooling of the engine and generator.

120V, 60 Hz Motors		Starting Amps
Hp motor	Running	RI type	Cap type	SP type
	Watts

LOAD APPLICATION

It is important to determine the total electrical load before it is connected to the generator. The two major factors in determining the life of a generator head are: heat build up, caused by overloading the generator and corrosive contaminants, that attack the wiring insulation. If the generator is overloaded, the wires

1/6

1/4

1/3

1/2

1

11/2

2

3

5

525

700

875

1175

1925

2400

2900

4075

6750

7-11

9-15

11-18

15-25

24-40

30-50

36-60

51-85

84-140

9-18

12-23

14-29

20-40

32-64

40-80

48-96

68-136

112-224

16-22

22-32

26-35

NA NA NA NA NA NA

become excessively hot and cause the insulation to break down, reducing its ability to resist corrosive contaminants. Over time the effectiveness of the insulation is eliminated and a dead short can result.

Always compare the generator nameplate data with that of the equipment to be used to ensure that watts, volts, amperage, and frequency requirements are suitable for operating equipment. The wattage listed on the equipment nameplate is its rated output. However, some equipment may require three to ten times more wattage than its rating on the nameplate, as the wattage is influenced by the equipment efficiency, power factor and starting system. NOTE: If wattage is not given on equipment nameplate, approximate wattage may be determined by multiplying nameplate voltage by nameplate amperage.

VOLTS	X AMPS	= WATTS
Example: 120V	X 5A	= 600W
When connecting	a resistive load such as

incandescent lights, heaters or common electric power tools, a capacity of up to the generator full rated wattage output can be used.

When connecting a resistive-inductive load such as a fluorescent or mercury light, transformers or inductive coils, a capacity of up to 0.6 times the generator’s full rated output can be used.

Always allow the generator to reach operating speed before a load is applied.

STARTING ELECTRIC MOTORS

Electric motors require much more current (amps) to start than to run. Some motors, particularly low cost split-phase motors, are very hard to start and require 5 to 7 times more current to start than to run. Capacitor motors are easier to start and usually require 2 to 4 times as much current to start than to run. Repulsion Induction motors are the easiest to start and require 1.5 to 2.5 times as much to start than to run.

Most fractional motors take about the same amount of current to run them whether they are of Repulsion-Induction (RI), Capacitor (Cap), or Split- Phase (SP) type. The following chart shows the approximate current required to start and run various types and sizes of 120 volt 60 cycle electric motors under various conditions.

The figures given above are for an average load such as a blower or fan. If the electric motor is connected to a hard starting load such as an air compressor, it will require more starting current. If it is connected to a light load or no load such as a power saw, it will require less starting current. The exact requirement will also vary with the brand or design of the motor.

Generators respond to severe overloading differently than the power line. When overloaded, the engine is not able to supply enough power to bring the electric motor up to operating speed. The generator responds to the high initial starting current, but the engine speed drops sharply. The overload may stall the engine. If allowed to operate at very low speeds, the electric motor starting winding will burn out in a short time. The generator head winding might also be damaged.

Running the generator under these conditions may result in damage to the generator stator as well as the motor windings. Because the heavy surge of current is required for only an instant, the generator will not be damaged if it can bring the motor up to speed in a few seconds. If difficulties in starting a motor are experienced, turn off all other electrical loads and if possible reduce the load on the electric motor.

EXTENSION CORDS

When electric power is to be provided to various loads at some distance from the generator, extension cords can be used. These cords should be sized to allow for distance in length and amperage so that the voltage drop between the set and point of use is held to a minimum.

Current/Power		Maximum Extension Cord Length
Amps	Load	#10	#12	#14	#16
at	(watts)	Ga.	Ga.	Ga.	Ga.
240V		Cord	Cord	Cord	Cord
10	2400	250’	150’	100’	75’
20	4800	125’	75’	50’	25’
30	7200	60’	35’	25’	10’
40	9600	30’	15’	10’	*
50	12000	15’	*	*	*

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