Sima Products STP-3000 - Manual (Page 3)

SIMA STP- 3000 12V DC
Owner's Manual
1. Introduction
Your new Sima STP-3000 inverter is the most advanced DC to AC inverter available today from the SIMA family. It is designed to give you years of
dependable services everywhere in your RV, boat, service vehicle, office, shop or remote home.
Proper installation of the Sima STP-3000 is needed to obtain its best performance as instructed in this installation and operation manual. Please read
carefully before installing and using your Sima STP-3000. Statements marked 'CAUTION' and 'WARNING' in this manual call for special attention
about the Sima STP-3000.
“CAUTION” statements identify conditions or practices that could result in damage to your Sima STP-3000 or to other equipment.
“WARNING” statements identify conditions or practices that could result in personal injury or loss of life.
2. Working Principle of your Sima STP-3000
A Power Inverter electronically converts electricity of low voltage DC to 115V AC. Advanced power conversion technology has been incorporated in
the design of Sima STP-3000, leading to a smaller, lighter, and easier-to-use inverter.
2.1 Principle of Operation
The Sima STP-3000 first raises low
voltage DC to 145 volts DC using modern high
frequency power conversion techniques, and then
converts the high voltage DC into 115 volts,
60Hz AC using advanced power MOSFET
transistors in full bridge configuration.
High surge capability to operate tough reactive
loads like fluorescent lamp ballasts and inductive
motors are incorporated.
Figure 1. SIMA STP- 3000 – Principle of operation
AC OUTPUT
CHASSIS GND GND NEUT LINE
INVERTER SECTION
170 V DC
POWER
MOSFET
DC INPUT
-
+
DC-DC
CONVERTER
2.2 SIMA
STP-3000 Output Waveform
The Sima STP-3000 generates "Quasi-Sine Wave" or
"Modified Sine Wave" waveform for its AC outputs
(Figure 2). It is designed to have characteristics similar
to the sine wave shape of utility power.
This waveform is suitable for most AC loads found in
electronic equipment, transformers, and motors. It is
also superior to the square waves produced by other
DC to AC inverters.
CAUTION: Do NOT Use Sima STP-3000 with the
following RECHARGEABLE APPLIANCES
Some rechargers for small nickel cadmium batteries
can be damaged if connected to the STP-3000
including the following equipment types:
1). Small battery operated appliances such as
flashlights, razors, and night-lights that plug
directly into an ac receptacle to recharge.
2). Some battery pack chargers for hand power tools
with warning labels stating that dangerous
voltages are present at the battery terminals.
Figure 2. Waveform of Modified Sine Wave
GND LIN
The vast majority of battery-operated equipment uses separate chargers or transformers that are plugged into AC receptacle to produces low voltage
outputs and hence would not have this problem. SIMA’s STP-3000 will power safely with less than 30-volt dc-output adapters or chargers.
The Sima STP-3000 is designed to have a True RMS (root mean square) voltage of 115 volts, the same as AC power. Most digital and analog AC
voltmeters are calibrated to the MEAN of the waveform rather than the true RMS value and such meters will not read the true RMS voltage of a
modified sine wave correctly. True RMS reading voltmeters (such as Fluke 87, Fluke 189, Fluke 8060A, Beckman 4410, or Tektronix TDS 220)
must be used to accurately measure the output voltage of your Sima STP-3000.
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