AC Master 12/500 Pure Sine Wave Inverter 500 W 12 V – Mastervolt

Mastervolt’s AC Master 12/500 inverter converts 12 V battery power into 230 V pure sine wave AC, ideal for supplying sensitive onboard loads such as domestic appliances, electric galley equipment and power tools. The true sine wave output is essential for equipment that requires a stable, clean voltage, unlike modified sine inverters that can cause faults on delicate loads.

Continuous output is 500 W at 25 °C, derating to 400 W at 40 °C for thermal management, with surge capability up to 800 W for 5 seconds—sufficient to start loads with high inrush. Declared efficiency is 90%. No‑load draw in power‑save mode is 4 W (0.33 A), limiting battery drain at anchor or alongside. Recommended battery capacity is at least 100 Ah, with input current at nominal load of 37.5 A and minimum DC fusing of 2 × 40 A. A 1.5 m DC cable is included.

Integrated galvanic isolation electrically separates the DC input from the AC output. Cooling is natural or fan‑assisted depending on load, with automatic shutdown at 50 °C. Protections include overload, short circuit, over‑temperature, and high/low battery voltage (shutdown at 16 V and 10 V respectively). Protection rating IP23. CE and E‑mark compliant, and certified for marine installations to ABYC A‑31. The AC outlet is IEC type, with IEC plug supplied.

Main features

• Pure sine wave (true sine wave) compatible with sensitive equipment such as domestic appliances, electric galley gear and tools requiring a stable 230 V 50 Hz supply
• 500 W continuous, 800 W surge for 5 seconds to handle start‑up inrush from loads such as motors and refrigerators
• Integrated galvanic isolation electrically separates battery and loads, eliminating interference and cross‑faults between circuits
• Power‑save mode with 4 W idle draw to reduce battery drain during extended lay‑ups
• Comprehensive protection against overload, short circuit, over‑temperature, high (16 V) and low (10 V) battery voltage, with 4 alarm modes and LED display
• Certified for onboard use CE, E‑mark and compliant for marine installations to ABYC A‑31