Blue Bird Coachworks 450 LXi, Owner'S Manual

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450 LXi Owner Manual 4-3 Inverter
Rev. “C”
~ 4-3-13 ~
4-3.5 General Information
4-3.5.1 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 both with the appropriate regulator or charge controller to
bring the DC source within the operating range of the inverter.
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.
There are three available inverter types and they are distinguished by the type of AC output wave form they produce. Below is
a graphic of the three types of inverters. The coach is supplied with a true Sine Wave Inverter.
Sine Wave Inverter
Sine Wave Inverters produce an AC output waveform like power produced by the electric utility companies and rotating
generators. The sine wave inverter’s waveform 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 waveform. 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.
Modifi ed Sine Wave Inverter
Modifi ed Sine Wave Inverters are sometimes called “quasi sine wave inverters” or “modifi ed square wave inverters.” Modifi ed
sine wave inverters generally cost more than square wave inverters because they contain additional electronic circuitry to
produce tru RMS regulated AC output. Modifi ed sine wave inverters have higher AC peak voltages than square wave inverters,
and automatically control the width of the AC output waveform to regulate the output voltage (pulse-width modulation).
The shape of the modifi ed sine wave inverter’s waveform 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 waveform 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 modifi ed 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.