Learning how to calculate the size of an inverter according to your needs can be a tricky task, especially if you are unfamiliar with how inverters work or how much power they need to produce. Inverters are useful devices, but to make accurate estimates or find the right answer, you might have some questions about inverters.
Details
When calculating the power of a solar inverter, some common questions are often mentioned:
· Can I use a refrigerator on the inverter?· What can a 3000w inverter be used for?
· How much power do I need from an inverter to run a microwave?
Of course, there are more questions. However, whether you need a large or small inverter, you can calculate the appropriate size through our inverter sizing calculator.
First, how much power does a power inverter use? An inverter needs to meet two requirements: peak or surge power, and typical or continuous power.
Surge is the maximum power that an inverter can provide, usually only for a short time (unless specified in the inverter specifications, it usually does not exceed one second). Some appliances, especially those with motors, require much higher starting surges than when running. Pumps, compressors, and air conditioners are the most common examples; another common example is freezers and refrigerators (compressors). You want to choose an inverter with a continuous rating that will handle the surge rating of your equipment so that you don't prematurely burn out the inverter. Do not rely on the inverter's surge to start the device because, unless the manufacturer claims that the surge time is longer than normal, the inverter does not like operating in surge mode.
Typical is what the inverter must provide on a steady basis. This is the continuous rating. It is usually much lower than the surge. For example, this would be the power after the refrigerator motor starts for a few seconds, or the power needed to run a microwave, or the total power of all loads combined. (Please refer to the end of this section for notes on device power and/or nameplate ratings.)
How big of an inverter do I need?
Finding the right size inverter for your needs is simple; just add up the necessary power for the items you want to power. Whether you are looking for what size inverter is best for your house or something as simple as an inverter to power your TV, the appropriate size is based on measurements of typical power and necessary surge power. If your equipment has startup requirements, you need to provide additional surge power to avoid wearing out the inverter.
Inverter wattage and amperage calculator: Finally, it may be necessary to find the amperage required by the inverter to measure how much battery capacity the inverter needs. This is very useful for finding the right battery size for your inverter (you can use our convenient guide to calculate) or measuring the necessary voltage. You can use the following formula to determine the size:
Volts * Amperes = Watts or Watts / Volts = Amperes 1250-watt example:
1250 / 120 VAC = 10.41 Amps AC (current number on the device) or
1250 / 12 VDC = 104.1 Amps DC (battery power consumed per hour)
For example:
First, you need to determine which items need to be powered during an outage and the duration of the power supply. Here is a short example (watt requirements vary):
* Light - about 200 watts
* Refrigerator - about 200 watts
* Coffee maker - about 800 watts
* Radio - about 50 watts
* Heater - about 1000 watts
The total required power is 2250 watts. The refrigerator and heater have startup power requirements, so let's provide twice the continuous wattage for startup requirements. 2250 * 2 = 4500 watts
To get a total power estimate for all the items you plan to power with the inverter, check this convenient estimator. This useful measurement tool can save you time and provide accurate measurements.
Second, choose an inverter. For this example, you will need a power inverter capable of handling 4500 watts. The actual continuous power requirement is 2250, but when determining the size of the inverter, you must plan for startup so that the
