North Star M165938N Power Load Planning & Management cont’d, Example, Staggering Loads

Power Load Planning & Management (cont’d)

	Running		Running
Device	Watts	Device	Watts
Freezer	800 (b)	Submersible pump (1 HP)	2000 (a)
Hair dryer	1200	Submersible pump (1/2 HP)	1500 (a)
Hand drill (1”)	1100	Sump pump	600 (a)
Hand drill (1/2”)	875	Table saw	2000 (a)
Hand drill (3/8”)	500	Television	500
Hand drill (1/4”)	250	Toaster	1000
Hedge trimmer	450	Vacuum cleaner	250
Home computer	150	VCR	70
Impact wrench	500	Water Heater	3000
		Weed trimmer	500

(a)Hard-starting motors require 3-5 times the rated running watts

(b)For extremely hard to start loads such as air conditioners and air compressors, consult the equipment dealer to determine maximum wattage

To calculate the running and starting wattage requirements for the devices you will be powering, follow these steps:

1.Make a list of all electrical devices you will be powering at the same time with the generator.

2.List the greater of the running or starting wattage next to each device as obtained from the devices’ nameplate or Table 1. If only the running wattage for a device with an electric motor is known, the starting wattage can be estimated to be at least 3 times the running wattage.

3.Add the wattages for all devices on your list. This total must be lower than the continuous output rating of your generator.

Example:

	Greater of Starting/Running
Device to be Powered	Wattage
Light Bulb	75 W
Refrigerator – 18 Cu. Ft.	1600 W
Microwave	700 W
Window AC	1800 W
Sump pump (1/3 hp)	2100 W
Total	6275W

In this example, the generator must have a continuous output of at least 6275 W in order to power all of the devices simultaneously.

STAGGERING LOADS

You can increase the number of devices your generator can power by staggering the load on the generator. For example, you could alternately power your refrigerator and air conditioner for limited periods of time -- powering only one of the devices at a time and never powering both at the same time.

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