Inverter for Emergency Home Backup Power
Article by Jon Hardwick
Using an inverter
for emergency power is by far the most common use. The Hurricane season is here
for those of you in the east and down south. I hope that this article will help
all of you to be more prepared in the likely event that power failure occurs.
Here are some helpful tips about running an inverter during a power outage.
purchase an inverter you will want to take a piece of paper and a pen and write
down all of the appliances that you feel are necessary to have during a power
outage. After you write down all that, you need to go to each one of the appliances
and look on the back or bottom for what is called the service tag. This tag will
show you a few important specs that help with picking the correct size of the
inverter. The first spec that you will most likely come across is the voltage;
this will either be 110,115, or 120vac.
cases you may find that the voltage is between 205vac and 240vac. You will need
a special inverter to run this appliance. We will get to that later.
The next spec
you will find will be the Amps. For example this should read like this: 6.0a or
6.0 amps. What you will do now is take the volts--lets say 115--and multiply by
amps 6.0 and this will give you 690 watts. The equation should look like this
Volts x Amps = Watts or in this example 115 x 6.0 = 690. Ok, Now that we got that
out of the way we can start sizing an inverter that is going to work well during
a power outage.
most common inverter sold for emergency home back-up power is a 1750 watt. The
reason for this is that most people want to hook it up to their car, and the 1750
is perfect for most vehicles and will run most appliances. When you hook the inverter
up to your vehicle, to run the inverter you will want to try to keep the inverter
close to the battery, and out of any weather. I get a lot of calls about why inverters
sometimes won't work when they are hooked to the vehicle this way. Most people
hook these up with jumper cables. This is not the best way to do this. Jumper
cables do not give a proper connection to the inverter. The best way to hook an
inverter up is with a ring terminal that fits properly over the inverter post.
Next we have
to cover how the battery will hold a charge. You will want to keep the vehicle
running while the inverter is hooked up. This will allow the vehicle's charging
system to keep a charge on the battery while the inverter is in use. If the car
is off, the inverter will still work. However, for prolonged use the inverter
will work best if the vehicle is running. This just about covers using an inverter
for emergencies with a vehicle.
an inverter for emergency back-up power in a home without a vehicle there are
a number of ways to accomplish this. First you can have, say, two 12 volt batteries
hooked in parallel, and one inverter. This will give you enough power to run say
a refrigerator off and on for two days or so depending on the size of the batteries.
If you decide to do this you may want to have at least one back-up battery for
the system in case power failure exceeds your battery time.
The next option
is for complete home back-up. This is the best option, but one of the most expensive.
The system will require a large bank of batteries at a higher voltage, say 24
volt or 48 volt. They do make 12 volt systems, but they are less efficient. The
best batteries to use in a large bank like this are the 6 volt batteries either
made for solar or golf carts. They have a much higher reserve time and are cost
effective. The next component is an inverter/charger. These are great for home
back-up. They have three key components: an inverter, a charger, and a transfer
switch. Inverter-chargers come in sizes ranging from 1500 watts to 5500 watts.
The battery chargers that are included range from 70 amps to 150 amps and will
charge the input DC voltage of the inverter (12V, 24V, or 48V). This system is
a lot more complex than that of a inverter and battery. Most of the inverter/chargers
do not have built in AC outlets and require an electrician or professional solar
installer to hook them up.
The way that
the inverter/charger will work is that the inverter will work when the power is
off and the battery charger will charge and maintain the batteries while the power
is on. Since the battery charger that is included is a three stage battery charger
with smart charging capabilities it is safe to leave the batteries hooked up to
this at all times. The internal transfer switch will allow for automatic switching.
This means that you will not have to do anything when the power goes out. The
inverter/charger will start running all of the appliances you have selected all
by itself. Even though the inverter/chargers are more expensive they are much
more convenient and you won't even know that the power went out.
Now that we
covered the home back-up without a vehicle, let's talk about 240vac appliances.
Even though there are inverters that will work for this you may want to consider
not running them during a power outage because of the large draw from the batteries
that they have. If you must run a 240 vac appliance you will want to have a complete
separate system from the 110vac inverter system that is running the common household
appliances such as the refrigerator or lights.
I hope that
this information will help those of you who are faced with hurricanes and other
sources of power outages. You can find a great selection of power inverters at
www.donrowe.com. Any questions or comments would be
appreciated. You may email me at email@example.com.
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