What size generator do you need?

Getting a generator that can handle all your power generation needs is one of the most critical aspects of the purchasing decision Whether you are interested in prime or standby power, if your new generator can't meet your specific requirements then it simply won't be doing anyone any good because it can put undue stress on the unit and even damage some of the devices connected to it.

Dont fall into the trap of believing smaller generators can be used for standby electric power because they are not running all the time. This is not only a myth but can actually be very detrimental. Generator under sizing is one of the most common mistakes committed by buyers Not only does it involve the risks of damaging your new asset (the generator), but it can also damage other assets connected to it, create hazardous situations, and even limit overall productivity of the unit and/or the business relying on it If nothing else, the key thing to remember here is that more is always better than less, or put another way buy the biggest you can afford.
When calculating the “size/capacity” or wattage of the generator you need, there are two main considerations:
• Continuous Power (or running watts) is the wattage required for operation of your appliances under normal load. This may be some or all of the appliances depending on circumstances.
• Extra Peak Power (or startup watts) is the extra wattage required for appliances at startup or when they are running at their highest levels of power consumption.
Generally an average size home requires from 5000 to 7000 watts to power essential items.
Step 1: Review the chart below and identify the number of tools/ appliances that will be running at peak time. To determine your needs, total the watts for the items you would like to run at the same time . This provides you with the number of continuous or running watts your generator must supply.
Step 2: Now select the largest number of starting watts assigned to the items you wish to use.
Step 3: Total these two numbers and this will indicate the size generator required to meet your need.


To be on the safe side you may wish to add an extra 10%
Tools or Appliances
Surge Watts
Running Watts
Number of appliances
Tool / Appliance total watts
Lighting - Estimate 1 watt per sqare foot
0



Cell Phone Battery Charger
0
10


Christmas Lights (50-string, small) (RV/Camping/Tailgate)
0
20


Laptop Computer (Home/RV/Camping/Tailgate)
0
75


PDA, iPod, iPhone, Blackberry, Cell Phones
0
80


13-Inch TV (Home/RV/Camping/Tailgate)
0
100


Outdoor Buglight (RV/Camping/Tailgate)
0
100


AM/FM Radio / CD Player
0
100


20-Inch Box Fan
0
200


Video Game Console
0
200


Crockpot (Home/RV/Camping/Tailgate)
0
250


Desktop Computer
0
300


TV/DVD Combo (Home/RV/Camping/Tailgate)
0
300


Refrigerator – Dorm Size (Home/RV/Camping/Tailgate)
500
350


Food Processor/Blender (RV/ Camping/Tailgate)
500
350


Small Power Tools; Electric Drill 3/8-inch, jig saw…)
600
440


Color TV 27-Inch
0
500


Frying Pan / Skillet (Home/RV/Camping/Tailgate)
0
600


Refrigerator / Freezer
2200
600


Microwave Oven 750W
800
750


Single Element Hot Plate (Home/RV/Camping/Tailgate)
0
750


Washing Machine
2300
750


Coffee Maker (Home/RV/Camping/Tailgate)
0
800


Sump Pump
1400
800


Toaster – 2 Slot (Home/RV/Camping/Tailgate)
0
850


Furnace Fan Blower ½ HP
2300
875


Griddle/Deep Fryer (Home/RV/Camping/Tailgate)
0
1200


Toaster (Home/RV/Camping/Tailgate)
0
1250


RV Low Profile Air Conditioner 13,500 BTU – Heating
2300
1600


Circular Saw
3000
1500


Space Heater
0
1800


Electric Range
0
2100


Electric Water Heater
0
4000


Garage Door Opener (1/4 hp)
1000
550





TOTAL WATTS



If you have items that are not on the list, check the appliance, the product manual, or the manufacturer’s Web site for the device’s continuous and surge wattage. If amps are noted on the device, you can calculate watts by multiplying amps times the voltage. For example, a 7 amp device on 120v AC current would equal 840 watts (7 x 120 = 840).


Advantages of choosing the right size generator: Now that you have an idea on how to choose the appropriate size of generator to suit your needs, here's just a few of the benefits obtained by going through that process:
- No unexpected system failures
- No shutdowns due to capacity overload
- Increased longevity of the generator
- Guaranteed performance
- Smoother hassle-free maintenance
- Increased system life span
- Assured personal safety
- Much smaller chance of asset damage