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select_an_inverter

HOW TO SELECT
YOUR FIRST POWER INVERTER

How to Select An Inverter ✔

Choosing the right size of inverter depends on the power requirements of the appliances you expect to operate at any given time. You should consider both the continuous and surge power rating of your appliance. The continuous rating must be high enough to handle all the loads that may run at the same time. The inverter must also be capable of handling the starting surge of all loads that may start at the same time. Loads typically take many times their continuous rating to start.

Short Answer: The size you choose depends on the watts (or amps) of what you want to run (find the power consumption by referring to the specification plate on the appliance or tool). We recommend you buy a larger model than you think you'll need (at least 20% to 30% more than your largest load).


Example: You want to power a computer with a 17" monitor, some lights, and a radio.


Computer                   300Watts 
2x60 Watt Lights      120Watts 
Radio                           10Watts 
Total Needed             430Watts

For this application, you would minimally need a 500 W inverter, and should give some thought to a larger one, as there will likely be a time when you wish you'd bought a bigger model ... in this example, you might decide you'd like to run a fan while you compute, or let the kids watch TV.

Longer Answer: Determine Continuous Load and Starting (Peak) Load: You need to determine how much power your tool or appliance (or combination of them that you would use at the same time) requires to start up (starting load), and also the continued running requirements (continuous load).


What is meant by the terms "continuous-2000 watts" and "peak surge-4000 watts" is that some appliances or tools, such as ones with a motor, require an initial surge of power to start up ("starting load" or "peak load"). Once started, the tool or appliance requires less power to continue to operate ("continuous load")

Note: The wattage's given below are estimates. The actual wattage required for your appliances may differ from those listed. Check the nameplate on the appliance to determine the actual wattage required.

 

 

Pumps and Air Conditioners

Estimated Watts

* Well Pump 1/3 hp

750 (Running)
1400-3000 (Starting)

* Well Pump 1/2 hp

1000 (Running)
2100-4000 (Starting)

* Sump Pump 1/3 hp

800 (Running)
1300-2900 (Starting)

* Sump Pump 1/2 hp

1050 (Running)
2150-4100 (Starting)

* Air Conditioner
(7000 BTU to 10,000 BTU)

1000-1500 (Running)
2200-5000 (Starting)

Common Tools

Estimated Watts

Angle Grinder

900

Drill (1/4"-1/2")

500-960

Disc Sander

1200

Jig Saw

300-700

Band Saw

700-1200

Table Saw

1800

Cicular Saw

1400-1800

Chop / Cut Off Saw

1500-1800

Shop Vac 6.5 hp

1440

* Electric Chain Saw 14"

1200

* Airless Sprayer 1/2 hp

750

* Air Compressor 1 hp

2000

Common Appliances

Estimated Watts

Coffee Maker

600-1200

Keurig

1500 (max)
200-400 (continuous)

Blender

300-1000

Microwave
(600-1000 Watt Cooking Power)

1000-2000

Waffle Iron

800-1500

Hot Plate

750-1500

Electric Skillet

1000-1500

Toaster Oven

1200

Toaster

800-1500

Hair Dryer

1000-1875

Vacuum Cleaner

300-1500

Space Heater

750 / 1500

Clothes Iron

1000-1500

* Refrigerator

500-750

* Chest Freezer

600

* Washing Machine

500-1000

Furnace Fan

750-1200

Household Fan

50-120

Clock Radio

10-50

Stereo

30-100

Cell Phone Charger

10

Laptop Computer

20-75

MacBook Pro

85

iPad / Tablet

10-20

Desktop with Monitor

200-400

Inkjet Printer

15-75

Laser Printer

500 (continuous)
2000 (peak)

Photographic Strobe
(300 Watt-Second)

1200 (peak)

Aquarium

50-1000

TV 32" LED/LCD

50

TV 42" Plasma

240

Home Theater Projector

200

Blu-Ray or DVD Player

15

Satellite Dish / Receiver

20-30

Video Game Console
(Xbox / PS4 / Wii)

40-140

* Appliances and tools with induction motors (marked * in tables) may require from 3 to 7 times the listed wattage when starting. The start-up load of the appliance or tool determines whether an inverter has the capability to power it. Be sure to check the specific wattage requirements and operating instructions for appliances / tools to be used. Also, air conditioners are a very difficult load because of the high start-up surge. Use the Locked Rotor Amps to determine the start up surge requirement.

Rated vs. Actual Current Draw of Equipment✔

Most electrical tools, appliances and audio/ video equipment have labels that indicate the power consumption in amps or watts. Be sure that the power consumption of the item you wish to operate is less than inverter’s power. (If the power consumption is rated in amps AC, simply multiply by the AC volts (120) to determine the approximate wattage). The inverter will shut down if it is overloaded. The overload must be removed before the inverter will restart. Resistive loads are the easiest for the inverter to run. However, larger resistive loads, such as electric stoves or heaters, usually require more wattage than an average sized inverter can deliver. Inductive loads, such as TV’s and stereos, require more current to operate than do resistive loads of the same wattage rating. Induction motors, as well as some televisions, may require 2 to 6 times their wattage rating to start up. The most demanding in this category are those that start under load, such as compressors and pumps. To restart the unit after a shutdown due to overloading, remove the overload if necessary turn the power switch OFF then ON.