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Thursday, 5 January 2012

INVERTER CHARGERS DO'S AND DONT'S



ABOUT INVERTER CHARGERS
A fairly comprehensive summary about inverter chargers i.e uses & how to use them.


What does
a power inverter do, and what can I use one for?


A power inverter changes DC power from a battery into conventional AC power
that you can use to operate all kinds of devices ... electric lights, kitchen
appliances, microwaves, power tools, TVs, radios, computers, to name just a few.
You just connect the inverter to a battery, and plug your AC devices into the
inverter ... and you've got portable power ... whenever and wherever you need
it.

The inverter draws its power from a 12 Volt battery (preferably deep-cycle),
or several batteries wired in parallel. The battery will need to be recharged
as the power is drawn out of it by the inverter. The battery can be recharged
by running the automobile motor, or a gas generator, solar panels, or wind. Or
you can use a battery charger plugged into an AC outlet to recharge the battery.




What size inverter should I buy?


 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 10% to 20% more than your largest load).

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

Computer: 300 Watts
2 - 60 Watt lights: 120 Watts
Radio: 10 Watts
Total Needed: 430 Watts
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.
 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")

Helpful formulas:

To Convert AMPS to WATTS:

Multiply: AMPS X 120 (AC voltage) = WATTS
This formula yields a close approximation of the continuous load of the appliance
To Calculate approximate Startup Load:

Multiply: WATTS X 2 = Starting Load
This formula yields a close approximation of the starting load of the appliance,
though some may require an even greater starting load. NOTE: Induction
motors such as air conditioners, refrigerators, freezers and pumps may have a
start up surge of 3 to 7 times the continuous rating.
Most often the start up load of the appliance or power tool determines whether
an inverter has the capability to power it.

For example, you have a freezer with a continuous load of 4 amps, and a
start up load of 12 amps:

4 amps x 120 volts = 480 watts continuous

12 amps x 120 volts = 1440 watts starting load

You would need an inverter with peak-surge rating greater than 1440 watts.
FORMULA to convert AC Watts to DC Amps:
AC Watts divided by 12 x 1.1 = DC Amps

(this is the size vehicle alternator you would need to keep up with a specific
load; for example, to keep up with a continuous draw of 1000 watts, you would
need a 91 amp alternator)

Do I need Modified Sine Wave, or Pure Sine Wave?
Advantages of Pure Sine Wave inverters over modified sine wave inverters:

a) Output voltage wave form is pure sine wave with very low harmonic distortion
and clean power like utility-supplied electricity.

b) Inductive loads like microwave ovens and motors run faster, quieter and
cooler.

c) Reduces audible and electrical noise in fans, fluorescent lights, audio
amplifiers, TV, Game consoles, Fax, and answering machines.

d) Prevents crashes in computers, weird print out, and glitches and noise
in monitors.

e) Reliably powers the following devices that will normally not work with
modified sine wave inverters:

  • Laser printers, photocopiers, magneto-optical hard drives
  • Certain laptop computers (you should check with your manufacturer)
  • 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
  • X-10 home automation system
  • Medical equipment such as oxygen concentrators
 Modified Sine  Wave works well for most uses, and is the most common type of inverter on the market, as well as the most economical. Pure Sine Wave inverters (also called True Sine Wave) are more suited for sensitive electrical or electronic items such
as laptop computers, stereos, laser printers, certain specialized applications
such as medical equipment, a pellet stove with an internal computer, digital clocks,
bread makers with multi-stage timers, and variable speed or rechargeable tools. 
If you wish to use those items with an inverter, then choose a Pure Sine Wave
inverter. If you mostly want to run lights, TV, microwave oven, tools, etc, a
Modified Sine Wave inverter is fine for your needs.

 However, if you have any doubt about any appliance, tool or device, particularly laptop computers and medical equipment such as oxygen concentrators, we recommend that you check with its manufacturer to be sure it is compatible with a Modified Sine Wave inverter.
If it is not, choose  Pure Sine Inverters instead.

The difference between them is the Pure Sine Wave inverter produces a better
and cleaner current. They are also considerably more expensive. You might find
it practical to get a small Pure Sine Wave inverter for any "special need" you
may have, and also a larger Modified Sine Wave inverter for the rest of your applications.


How do I hook up the Inverter? What size cable should I use, and is it included?
Many small inverters (450 watts and under) come with a cigarette lighter adapter, and may be plugged into your vehicle's lighter socket (although you will not be able to draw more than 150 to 200 watts from the cigarette lighter socket). The small units also come with cables that can be clamped directly to a battery. If you want an inverter that will plug into your cigarette lighter, you must choose one that is 450 watts or less.
Larger inverters (500 watts and over) must be hard-wired directly to a battery. The cable size depends on the distance between battery and inverter, and will be specified in the Owner's Manual.
When connecting the inverter to the battery use the thickest wire available,
in the shortest length practical
.



General recommendations:
Inverter Size < 3 ft 3ft - 6ft 6ft < 10ft
400 Watts
8
6
4
750 Watts
6
4
2
1000 Watts
4
2
1/0
1500 Watts
2
1
3/0
2000 Watts
1/0
2/0
250
2500 Watts
1/0
3/0
350
3000 Watts
3/0
4/0
500
NOTE: These are general recommendations for inverters that utilize a single cable set (one positive and one negative cable) only and may not be correct for all inverters or applications. Additionally, some inverters require two or more cable sets and therefore may require a different cable size than listed.
Cable size recommendations may vary among inverter brands and models;
check the Owner's Manual for the model you purchase before you buy the wire for
it.

The maximum length generally recommended is 10', and shorter is better. If you need more length, it is much better to put it on the AC side (as with an extension cord from inverter to appliance) than on the DC side.



What type of battery should I use (automotive or deep cycle)?
Small Inverters: Most automobile and
marine batteries will provide an ample power supply for 30 to 60 minutes even
when the engine is off. Actual time may vary depending on the age and condition
of the battery, and the power demand being placed on it by the equipment being
operated by the inverter. If you use the inverter while the engine is off, you
should start the engine every hour and let it run for 10 minutes to recharge the
battery.

500 Watt and larger Inverters: We recommend
you use deep cycle (marine or RV) batteries which will give you several hundred
complete charge/discharge cycles. If you use the normal vehicle starting batteries
they will wear out after about a dozen charge/discharge cycles. If you do not
have a deep cycle battery, we recommend that you run the engine of your vehicle
when operating the power inverter.

When operating the inverter with a deep cycle battery, start the engine
every 30 to 60 minutes and let it run for 10 minutes to recharge the battery.

When the inverter will be operating appliances with high continuous load
ratings for extended periods, it is not advisable to power the inverter with the
same battery used to power your car or truck. If the car or truck battery is utilized
for an extended period, it is possible that the battery voltage may be drained
to the point where the battery has insufficient reserve power to start the vehicle.
In these cases, it's a good idea to have an extra deep cycle battery for the inverter
(installed close to the inverter), cabled to the starting battery. It is recommended
to install a battery isolator between the batteries.


How long can
I run the inverter on my battery?


To estimate how long a battery/appliance combination will operate together,
use this handy calculator.
(Tip: If the calculator output equals 0 hours, the total Amp/Hrs of the battery bank are insufficient to run the load. Try adding additional Amp/Hrs to the battery bank field in order to run the desired wattage.)




1. Enter the voltage of your battery or bank of batteries. Battery Voltage
Battery Type Voltage Amp Hours
22 NF 12 50
24 NF 12 75
27 NF 12 100
8 D 12 200
2. Enter the total Amp/Hrs of the battery or bank of batteries. Amp/Hrs
3. Enter the combined Watt value of the appliances you plan to run from your battery. Watts
Examples Watts
19" Color TV 100
Circular Saw 1500
Computer System 300
Microwave Oven 1100
Power Drill 400
Toaster 1000
Represents actual power consumption as measured on sample products. 
4. Click the Calculate button to see the number of hours your configuration should run. hour(s) of operating time, approximate. Based on fully charged batteries.
Tip: Deep cycle (marine) batteries generally have the highest reserve ratings. They are also capable of withstanding repeated drains of power and recharging. Tip: Engine start batteries should not be discharged below 90% charged state, and marine deep cycle batteries should not be discharged below 50% charged state. Doing so will shorten the life of the battery based on most battery manufacturers recommendations. Note: If you intend to use power tools for commercial use, or any load of 200W for more than 1 hour regularly (between battery recharging) we recommend installing an auxiliary battery to provide power to the inverter. This battery should be a deep cycle type and sized to meet your run time expectations with the engine off. The auxiliary battery should be connected to the alternator through an isolator module to prevent the inverter from discharging the engine start battery when the engine is off.
How do I connect two or more batteries? It may be advisable to operate the inverter from a bank of 12 Volt batteries of the same type in a "parallel" configuration. Two such batteries will generate twice the amp/hours of a single battery; three batteries will generate three times the amp/hours, and so on. This will lengthen the time before your batteries will need to be recharged, giving you a longer time that you can run your appliances. You can also connect 6 Volt batteries together in "series" configuration to double the voltage to 12 volts. Note that 6 Volt batteries must be connected in pairs.

 General Safety Precautions and Installation Tips:
  • 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.


  deep cycle batteries

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