The inverter is a basic
component on most systems which converts low voltage DC power
from the batteries into high voltage (120 or 240) AC power as
Most inverters we sell
produce only 120 VAC as once the major electric appliances are
replaced with gas appliances (range, oven, water heater, heating
and air conditioning),there is little need for 240 VAC power.
Exceptions include larger submersible pumps and shop tools which
can be powered either by the generator or a step-up transformer
(or by a larger or second inverter).
Two types of inverters
are modified sine and sinewave. Least expensive are modified sinewave
units which will operate all but the most sophisticated electronic
devices. Sinewave inverters produce power nearly identical to
the utility grid, will operate those delicate laser printers,
etc. but cost m
ore per watt of output.
While an inverter is a substantial portion of the cost of a system,
it is really a subsystem that includes a number of additional
components. To make a safe, reliable installation one should provide
- Inverter to battery
Because of the high current required on low voltage circuits,
this cable is large, commonly #2/0 to
#4/0 in size. Smaller conductors than required are unsafe and
will not allow the inverter to perform to its full rating.
- DC input disconnect
and overcurrent protection
It is important to have a safe installation with a properly
sized DC rated, UL listed disconnect. Typically the disconnect
works in conjunction with an overcurrent protection device such
as a fuse or breaker. These components are installed in an electrical
enclosure which can also house shunts.
Are used to read the amperage flowing between the battery and
inverter. This device is installed in the negative conductor.
It can easily be housed in the disconnect or its own enclosure.
- AC output disconnect
and overcurrent protection
I If the breaker panel which is fed from the inverter is adjacent
to the inverter, then the main breaker will serve as the inverter
output disconnect and overcurrent protection. If, however, this
panel is not grouped with the inverter, then a separate unit
should be installed. This also holds true with AC circuits coming
to the inverter from a generator or utility source. A second
breaker may be needed if these breakers are not grouped.
Inverters with built-in
Many of today's inverters incorporate battery charging circuitry.
This is easily and economically accomplished because of the design
of most inverters. Inverters step up low voltage and change DC
power to AC power. Battery chargers do the reverse of this. Additional
circuitry is all that is required to add a second function and
economically create an Inverter/Charger.
Transfer switches are
also incorporated into these Inverter/Chargers so that the AC
loads can be powered directly from the generator when the battery
charger is operating.
- Continuous wattage
Hour after hour, what amount of power in watts can the inverter
- Surge Power
How much power and for how long can an inverter deliver the
power needed to start motors and other loads.
How efficient is the inverter at low, medium
and high power
draws. How much power is used at idle.