5
Form
122039
Technical Description
3.1 DC to AC Power Inverter:
A power inverter supplies usable 120VAC, 60Hz power by inverting DC power storage in
a bank of batteries. The inverter has an optional battery charger (“B3” option, 12W8
model only) and an automatic fast transfer switch (“T” option). See section 3.2 for all
options available with this inverter model.
A customer-supplied remote “On/Off” switch connected to the violet wire extending from
the inverter module controls the inverter. The “R” or R3” options provide inverter On/Off
control and status display in a LED remote control/status panel, which is connected to
the inverter module through a flat 8-conductor telephone type cable.
The system has two operational modes when a transfer switch “T” option is included:
Inverter mode and external power mode (refer to section 3.2.1).
3.1.1 Inverter Mode:
The inverter converts DC power from batteries to usable 120
VAC, 60 Hz power. The direct current (DC) that enters the inverter is filtered by a large
input capacitor and switched “On” and “Off” by the Metal Oxide Silicon Field Effect
Transistors (MOSFET) at a rate of 60 cycles per second, and directed into the
transformer which steps the voltage up to 120 volts. The unit has a Digital System
Processor (DSP) to control the output voltage and frequency as the DC input voltage
and/or output load varies. The signal output waveform shape is not sinusoidal; it has a
total harmonic distortion of 31% and a maximum single harmonic distortion of 25%.
