SureSine Classic

Compact, powerful and proven in demanding rural electrification and other demanding projects around the globe, the SureSine Classic inverter is the right tool for DC to AC power conversion in small residential, mobile and recreational, and light industrial applications where environmental extremes are a consideration.   A cast, anodized aluminum enclosure and encapsulated circuitry—plus an effectively sealed, fanless design– ensure long-term, dependable operation under the harshest conditions.  Access more information below about the SureSine Classic, and also consider our new expanded SureSine off-grid inverter line.

Models: SI-300-115V-UL (60 Hz), SI-300-220V (50 Hz),

Specifications and Certifications by Model


SI-300-115V-UL (60 Hz)

SI-300-220V (50 Hz)

Continuous Power Rating 300 Watts @ 25C 300 Watts @ 25C
Pek Power Rating (15 min.) 600 Watts @ 25C 600 Watts @ 25C
DC Input Voltage 10.0V – 15.5V 10.0V – 15.5V
Waveform Pure sine wave Pure sine wave
AC Output Votage (RMS) 220V or 115V +/– 10% 220V or 115V +/– 10%
AC Output Frequency 50 or 60 Hz +/– 0.1% 50 or 60 Hz +/– 0.1%
Nominal Battery Voltage 12V 12V
Peak efficiency 92% 92%
Total Harmonic Distortion (THD) <4% <4%
Self Consumption (Inverter ON – no load) 450mA 450mA
Self Consumption (Inverter OFF) 25mA 25mA
Self Consumption (Standby) 55mA 55mA
Operating Temperature Range -40 C to +45C -40 C to +45C
Warranty 2 Years 2 Years
CE and RoHS compliant Yes Yes
ETL Listed [UL-458] Yes
FCC Class B Part 15 Compliant Yes Yes
Manufactured in a Certified ISO 9001 Facility Yes Yes
Key Features and Benefits
  • Improved Load Operation – Pure sine wave provides quality AC equivalent to grid power. Toroidal transformer design generates good wave form throughout the range of input voltages. Handles 200% surge up to 600W
  • High reliability – No internal cooling fan or other moving parts. Uses epoxy encapsulation, conformal coating, stainless steel hardware and an anodized aluminum enclosure to protect against harsh tropical and marine environments
  • More power available – High efficiency and low self consumption maximizes power to the loads. Automatic stand-by reduces consumption during no load consumption
  • Speaks Modbus, and SNMP with the optional EMC-1 adapter
  • Other Features
    • More Information – the two LEDs provide important information to the user about system status and any fault conditions. An optional digital meter may be connected to the SureSine to display additional system information.
    • Remote On/Off – improves safety by making it easy to install the SureSine in an inaccessible location or enclosure. Reduces system cost by avoiding the need to add an AC safety disconnect to the system.
    • Adjustability & Communications – four DIP switches provide easy adjustability of several system parameters. Additional adjustability is possible using Morningstar’s USB MeterBus Adapter (UMC-1) to connect to a PC. Free 3rd-party MODBUS software is available for custom programming. IP-based communication, including SNMP, is enabled through Morningstar’s Ethernet MeterBus Converter (EMC-1).