The modified sine wave produced by the MAXX 750 SST inverter has an RMS
(root mean square) voltage of 110 volts, which is the same as standard household
power. Most AC voltmeters (both digital and analog) are sensitive to the average
value of the waveform rather than the RMS value. They are calibrated for RMS
voltage under the assumption that the waveform measured will be a pure sine
wave. These meters will not read the RMS voltage of a modified sine wave cor-
rectly. They will read about 20 to 30 volts low when measuring the output of the
inverter. For accurate measurement of the output voltage of this unit, use a true
RMS reading voltmeter such as a Fluke 87, Fluke 8060A, Fluke 77/99 series,
Beckman 4410, or Triplett 4200.
FIGURE 4 -
Modified Sine Wave and Sine Wave Comparison
6
4. INSTALLATION
4.1 POWER SOURCE REQUIREMENTS
The power source must provide between 10.5 and 15.5 volts DC and must be
able to supply the necessary current to operate the load. The power source may
be a battery or a well-regulated DC power supply. To obtain a rough estimate of
the current (in amperes) the power source must deliver, simply divide the power
consumption of the load (in watts AC) by 10.
Example: If a load is rated at 750 watts AC, the power source must be able to deliver:
750 divided by 10 = 75 amperes
CAUTION:
The MAXX 750 SST must be connected only to batteries with a nominal
output voltage of 12 volts. The unit will not operate from a 6 volt battery
and will sustain permanent damage if connected to a 24 volt battery.
4.2 CONNECTION TO POWER SOURCE
The MAXX 750 SST comes equipped with battery clip cables for connection to the
power source:
CAUTION:
Do not use with positive ground electrical systems (the majority of modern
automobiles, RVs, and trucks are negative ground).
To operate at full 750 watts output, either use the battery clip cable (supplied) or
directly wire to the power source with user supplied wire and fuse. Use wire #8
AWG for lengths of four feet or less and #6 AWG for lengths to 10 feet.
