Inverter Buying Guide

Inverter has become a necessity than a luxury with frequent power cuts. People now want to run all home appliances including air conditioners, televisions and refrigerators for their convenience.

A power inverter converts 12V DC power to standard household 230V AC power, which allows you to run AC electrical equipment in case of emergencies or simple convenience.

TYPICAL USES OF INVERTERS

Inverters normally have one or more standard outlets to power laptops, small-screen TVs, video game players or portable DVD players and other devices. A DC to AC power inverter is great for camping at parks that do not provide electricity. The toaster, blender, and boom box can all still be used.

FEATURES OF INVERTERS

Ground Fault Protection

Inverters that have built-in GFCI protection are advised for powering portable electrical devices specially if used outside the house. Ground fault protection is a feature that instantly turns off the inverter if it gets damp or wet. The inverter then resets, senses the conditions and turns itself back on if the problems have been resolved. The GFCI feature protects the user from electrical shocks and the potential risk of a fire.

Transfer Switch

Some power inverters have a built-in transfer switch so you can switch from inverter power to utility power when available. The transfer switch allows external power to be transferred to appliances automatically. Typically this feature is found on more expensive high-end inverters

Solar Power Support

A power inverter is also an essential part of a solar power system. It converts the DC power generated by solar panels and stored in 12V batteries to 230V AC power suitable for household or industrial use. These systems can be costly, as they often involve additional electrical work and equipment to incorporate the system into a household’s current electrical system.

POWER INVERTER OR GENERATOR?

Whether to use an inverter or a generator depends on the type of load and how often you will need emergency AC power. Generally, an inverter is more economical power alternative to run items under 1000W, suitable for small appliances, TVs, VCRs, DVD players and other low load devices. If you plan to operate a refrigerator, freezer, washer, dryer or well system, then a generator is a better choice. If your planned power consumption exceeds 2000W, you should choose a generator, as the draw in the battery will rapidly deplete its power.

HOME APPLIANCE POWER USAGE

The typical usage of power appliances which you can use for approximate calculations is as in the table below ( do check the actual appliances wattage for caculating wattage):

AppliancePower (in Watts)Starting (in Watts)
Fan100200
Tubelight50100
TV120240
Laptop75100
Washing machine – with heater12002400
Washing machine – without heater20003200
Air Conditioner (1.5T)22004000
Air Cooler10002000
Refrigerator (150W)150300

CHOOSING THE RIGHT INVERTER SIZE

Power inverters come in many sizes, measured in watts (W). The amount of wattage you will require depends on the total draw of the devices you’d like to use.
Many appliances and power tools have their wattage rating indicated on the product itself. Wattage rating can also be calculated by using this formula:

Volts x Amps = Watts

To determine if several appliances can be operated at the same time, simply add up their wattage ratings to see if the total falls within the specifications of the power inverter. For example, if you have a two-outlet inverter and will be plugging in 2 devices at once, add up the total wattage of both devices, then add at least 50% more to account for peaks or spikes in the power draw. For example if your DVD player draws 100W and your laptop another 100W, a minimum 300W inverter ((100W + 100W) x 150% = 300W) is recommended.
Make sure the power of the inverter is listed as “continuous”. Some inverters are listed at a certain wattage, but can only draw that wattage for a short period of time (i.e.: 5 minutes) and then will shut off, reset themselves and resume functioning. These outages can be frustrating to you and harmful to the device you are powering.
If the item is motor driven, it requires additional start-up (surge) wattage (typically 2-3 times the continuous wattage required) to start the device. For example, a saw that runs at 700W might require 1400W to start up. If your inverter only supplies 1000W, you will not be able to start it up. In this case, you would want to select an inverter rated at least 1400W surge to handle start-up needs.

TYPES OF INVERTERS

Power inverters produce one of two different types of wave output:

  • Modified Sine Wave
  • True Sine Wave

Modified Sine Wave Inverter

Modified sine wave inverters deliver power that is consistent and efficient enough to run most devices adequately. These types of inverters are the most popular and affordable. They are also small and highly efficient. The Vector power inverter line is based on modified sine wave technology.

True Sine Wave Inverter

True sine wave inverters are the most expensive, but they also deliver the most consistent, highest quality wave output. Some sensitive equipment requires a true sine wave, like laptop computers, tool battery chargers, professional audio/video equipment, certain medical devices and variable speed tools. If you aren’t sure if the device you want to use requires a true sine wave or not, call the manufacturer to ask. Any AC device will run on a true sine wave inverter, whether it requires it or not.



Modified and True Sinewave Inverter Output

Advantages of True Sine Wave Inverter

  • Output voltage wave form is pure sine wave with very low harmonic distortion and clean power like utility-supplied electricity.
  • Inductive loads like microwave ovens and motors run faster, quieter and cooler.
  • Reduces audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, Game consoles, Fax, and answering machines.
  • Prevents crashes in computers, weird print out, and glitches and noise in monitors.
  • Reliably powers the following devices that will normally not work with modified sine wave inverters:
    • Laser printers, photocopiers, magneto-optical hard drives
    • Certain laptops and computers
    • Some fluorescent lights with electronic ballasts
    • Power tools employing “solid state” power or variable speed control
    • Some battery chargers for cordless tools
    • Some new furnaces and pellet stoves with microprocessor control
    • Digital clocks with radios
    • Sewing machines with speed/microprocessor control

BATTERY BASICS FOR INVERTERS

See Inverter Battery Buying Guide – Brands, Price, Reviews, Models

SAFETY AND INSTALLATION TIPS FOR INVERTERS

Always use a power inverter that is rated high enough for the device(s) you are running and avoid adapters that would allow more outlets than the unit is designed to accommodate.

  • Place the inverter on a reasonably flat surface, either horizontally or vertically.
  • The inverter should not be installed in the engine compartment, due to possible water/oil/acid contamination, and excessive heat under the hood, as well as potential danger from gasoline fumes and the spark that an inverter can occasionally produce. It’s best to run battery cables to a dry, cool inverter mounting location.
  • Keep the inverter dry. Do not expose it to rain or moisture. DO NOT operate the inverter if you, the inverter, the device being operated, or any other surfaces that may come in contact with any power source are wet. Water and many other liquids can conduct electricity which may lead to serious injury or death.
  • Avoid placing the inverter on or near heating vents, radiators or other sources of heat. Do not place the inverter in direct sunlight. Ideal air temperature is between 50° and 80° F.
  • In order to properly disperse heat generated while the inverter is in operation, keep it well ventilated. While in use, maintain several inches of clearance around the top and sides of the inverter.
  • Do not use the inverter near flammable materials. Do not place the inverter in areas such as battery compartments where fumes or gases may accumulate.
  • Inverters work best with a battery that is in good condition and fully charged. A weak battery will be drained easily if demands are too high. This could leave you stranded so be sure to check the battery’s condition before using a power inverter in a stationary vehicle.
  • Make sure the inverter is properly ventilated. Even a small inverter generates heat. Check to see if there is an internal fan with any inverter over 100 Watts. Place the inverter in a well-ventilated area when in use.
  • Check the owner’s manual for the proper wire size for battery cables when connecting the inverter to the battery. Most manufacturers recommend 4 to 10 feet of cable length, depending on the inverter. Avoid aluminium wire because it has higher resistance to current flow than copper wire.

Leave a Reply