INVERTERS - GENERAL INFORMATION
page 4
Why an inverter is needed
The utiliti grid supplies you with alternating current (AC) electricity. AC is the standard
form of electricity for anything that “plugs in” to the utility power. Direct current (DC)
electricity flows in a single direction. Batteries provide DC electricity. AC alternate its
direction many times per second. AC is used for grid service because it is more practicle
for long distance transmission. For more details read
“Characteristics of Sinusoidal
ACPower”
on page 7.
An inverter converts DC to AC, and also changes the voltage. In other words, it is a
power adapter. It allows a battery -based system to run conventional AC appliances
directly or through conventional home wiring. There are ways to use DC directly, but for
a modern lifestyle, you wil need an inverter for the vast majority, if not all of your
loads
(in electrical terms, “loads” are devices that use electrical energy)
.
Incidentally, there is another type of inverter called grid-interactive. It is used to feed solar
(or other renewable) energy into a grid-connected home and to feed excess energy back
into the utility grid. This inverter is
NOT grid interactive
.
Inverter should meet the application
To choose an inverter, you should first define your needs. Where is the inverter to be used?
Inverters are available for use in buildings (incuding homes), for recreational vehicles,
boats and portable applications. Will it be connected to the utility grid in some way?
Electrical conventions and safety standards differ for various applications, so don’t improvise.
Electrical standards
The DC input voltage must conform to that of the electrical system and battery bank.
12 volts is recommanded for small, simple systems. 24 and 48 volts are the common
standards for higher capacities. A higher voltage system carries less current, which
makes the system wiring cheaper and easier.
The inverter’s AC output must conform to the conventional power in the region in order
to run locally available appliances. The standard for AC utility service in Europe is 230Vac
at frequency of 50 Hertz (cycles per second).
Power capacity -”Continuous” and “Surge”
How much load can an inverter handle? Its power output is rated in Watts. Read details
under
“Characteristics of Sinusoidal AC Power”
on page 7. There are two levels of
power rating - a
continuous rating
and a
surge rating
. Continuous means the amount
of power the inverter can handle for an indefinite period of hours. When an inverter
is rated at a certain number of Watts, that number generally refers to its continuous rating.
The
“surge power”
indicates the power to handle instantaneous overload of a few seconds
to provide the higher power required to start certain type of devices and appliances.
Содержание PST-15S-12E
Страница 33: ...www samlex com www samlex solar com...
