STARTING ELECTRIC MOTORS
Electric motors require much more current (amps) to start than to run. Some motors, particularly low cost
Most fractional motors take about the same amount of current to run them whether they are of
120V, 60 Hz Motors | Starting Amps | |||
Hp motor | Running | RI type | Cap type | SP type |
| Watts |
|
|
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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’ | * | * | * |
*Not recommended
CAUTION: Equipment damage can result from the low voltage caused by using an extension cord with a
1/6
1/4
1/3
1/2
1
11/2
2
3
5
525
700
875
1175
1925
2400
2900
4075
6750
NA NA NA NA NA NA
small wire size.
Use this chart to estimate the total load on your generator.
For Determining Generator Load Requirements
| Dev ice | Running Watts | |
| Air Conditioner (12,000 Btu) | 1700 (a) |
|
| Battery Charger (20 Amp) | 500 |
|
| Belt Sander (3”) | 1000 |
|
| Chain Saw | 1200 |
|
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 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.
| Circular Saw |
| 900 |
|
| Coffee Maker |
| 1000 |
|
| Compressor (1 HP) |
| 2000 (a) |
|
| Compressor (3/4 HP) |
| 1800 (a) |
|
| Compressor (1/2 HP) |
| 1400 (a) |
|
| Curling Iron |
| 700 |
|
| Dishwasher |
| 1200 |
|
| Edge Trimmer |
| 500 |
|
| Electric Nail Gun |
| 1200 |
|
| Electric Range (one element) |
| 1500 |
|
| Electric Skillet |
| 1250 |
|
| Furnace Fan (1/3 HP) |
| 1200 (a) |
|
| Freezer |
| 800 (b) |
|
| Hair Dryer |
| 1200 |
|
| Hand Drill (1”) |
| 1100 |
|
| Hand Drill (1/2”) |
| 875 |
|
| Hand Drill (3/8”) |
| 500 |
|
| Hand Drill (1/4”) |
| 250 |
|
| Hedge Trimmer |
| 450 |
|
| Home Computer |
| 150 |
|
| Impact Wrench |
| 500 |
|
| Jet Pump |
| 800 (a) |
|
| Lawn Mower |
| 1200 |
|
| Light Bulb |
| 100 |
|
| Microwave Oven |
| 700 |
|
| Milk Cooler |
| 1100 (a) |
|
| Oil Burner on Furnace |
| 300 |
|
| Oil Fired Space Htr (140,000 Btu) |
| 400 |
|
| Oil Fired Space Htr (85,000 Btu) |
| 225 |
|
|
|
|
|
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