Installation
TruSine 4.5 kW Inverter
Page 23
Owner’s Manual
A) Discharge the battery by placing the AC load on the system and operating the inverter, (remove shore
power input).
B) When the battery charge level is low, the inverter will turn off.
C) Apply shore power and observe the battery charger operation. Connect an ammeter to the DC cables
between the inverter and the battery to monitor the current (DC amps), and a volt meter to the battery to
monitor the battery voltage. The battery charger will step through its sequence and stop in the float
mode.
Step 14: The system is now ready for operation.
6
GENERAL INFORMATION SECTION
6.1 Generic Inverter Description
In general, an inverter converts DC electrical power into AC power. This power can be used to operate various
AC-driven appliances. Typical DC power sources include batteries that store electrical energy, power
generated from a vehicle alternator or renewable energy sources such as photovoltaic (solar) panels.
The most common battery systems are 12 or 24 volt. Some systems, however, operate on higher voltages
such as 32, 36, 48, or 120 volts. The most common inverter AC output power is 120 volts at a frequency of 60
Hz. Some inverters, however, are designed to produce 240 volts, or both 120 and 240 volts at 60 Hz. Because
some countries use power of different voltage and frequency (e.g., 230 volts at 50 Hz), inverters are available
to conform to these requirements.
The three available inverter types are distinguished by the type of AC output wave form they produce. This
wave form affects the AC loads they operate. This section provides an overview of these inverter types,
including the advantages and disadvantages associated with using each type.
Sine Wave Inverter
Sine wave inverters produce an AC output wave form like power produced by the electric utility companies and
rotating generators. The sine wave inverter’s wave form is characterized by the highest peak voltage and
smooth voltage transitions (no square wave components). Such inverters are the most costly of the three
inverter types because they contain additional electronics to produce the required wave form. A measure of the
sine wave quality is Total Harmonic Distortion (THD), and is expressed in a percentage. The lower the THD
the higher the quality of the sine wave power.
Modified Sine Wave Inverter
Modified sine wave inverters are sometimes called “quasi sine wave inverters” or “modified square wave
inverters.” Modified sine wave inverters generally cost more than square wave inverters because they contain
additional electronic circuitry to produce true RMS regulated AC output. Modified sine wave inverters have
higher AC peak voltages than square wave inverters, and automatically control the width of the AC output wave
form to regulate the output voltage (pulse-width modulation). The shape of the modified sine wave inverter’s
wave form includes a square wave component. It is stepped in such a way, however, to closely approximate
the true sine wave produced by the electric utility companies. Although this wave form has a higher peak
voltage than do square wave inverters, its peak voltage is not as high as a pure sine wave. Therefore, AC
loads containing power supplies might not always operate properly on the modified sine wave inverter.
Square Wave Inverter
The square wave inverter is a low cost device that produces a pure square wave AC power output. This AC
power can be an accurate 60 Hz frequency if it is crystal controlled. It does not have the necessary peak
voltage to properly operate many AC appliances that contain electronic power supplies (e.g., computers, TVs,
and VCRs). The square wave is appropriate when operating AC loads such as resistive heating devices.
6.2 Inverter
Sizing
Output Power Rating - Power output is an important consideration when purchasing an inverter. Power is
defined as the rate that a device produces (or uses) electrical energy. This rate is measured in watts or
kilowatts (one kilowatt equals 1,000 watts), or sometimes in voltamps. Voltamps are roughly equal to watts and
