Victron Energy Galvanic Isolator (VDI-16 / VDI-32 / VDI-64)

Protect Your Boat's Underwater Metals from Shore Power Corrosion

Every time you plug into shore power, low-voltage DC currents can travel through the earth wire and silently eat away at your hull, propeller, shaft, and through-hull fittings. The Victron Galvanic Isolator stops this galvanic corrosion at the source — blocking destructive stray currents while maintaining full ground fault protection for your vessel's electrical safety.

Victron's galvanic isolator uses a pair of anti-parallel diodes with a forward voltage threshold of approximately 1.4 VDC — higher than the galvanic potential difference between dissimilar underwater metals. This means corrosion-causing currents are blocked, but in the event of an AC fault, the diodes conduct immediately so your circuit breaker or residual-current device trips as it should. Safety is never compromised.

Why You Need a Galvanic Isolator

If your boat connects to shore power at a marina, dock, or mooring, galvanic currents from neighboring boats and the dock's grounding system can accelerate corrosion on your underwater metals — even if your own electrical system is perfect. Zinc anodes help, but they're sacrificial and can be consumed quickly in a busy marina. A galvanic isolator provides a permanent first line of defense that dramatically extends the life of your anodes and underwater hardware.

Key Features

• Blocks galvanic corrosion currents — prevents low-voltage DC from traveling through the shore power ground wire to your underwater metals
• Maintains full safety grounding — AC fault currents pass through unimpeded so breakers and RCDs trip normally
• IP67 waterproof rating — fully potted construction stands up to bilge water, spray, and harsh marine environments
• Anodized aluminum heat sink — robust, corrosion-resistant housing designed for long-term marine use
• Simple installation — wires inline with your green safety ground conductor, directly behind your shore power inlet
• M6 stud connections — secure, high-current terminal connections on all models
• Victron 5-year warranty — backed by one of the most trusted names in marine power

Choose the Right Size for Your Boat

Select the model that matches or exceeds your shore power inlet rating:

Installation Notes

• Mount vertically in a well-ventilated area with at least 10 cm (4 in) of clearance on all sides for airflow
• Install in the green safety ground conductor before any other grounding connections to the vessel — no ground connections should bypass the isolator
• Under normal conditions, heat sink temperature rise is less than 20°C, though the unit may get hot during fault current events
• Must be installed in a heat-resistant environment away from chemicals, solvents, and textiles
• All connections and safety features must comply with locally applicable electrical regulations (ABYC E-11 in the US)

Frequently Asked Questions

What's the difference between a galvanic isolator and an isolation transformer?
A galvanic isolator blocks only low-voltage DC galvanic currents on the ground wire while keeping the safety ground connected. An isolation transformer completely separates the boat's electrical system from shore power, providing more comprehensive protection but at significantly higher cost, weight, and complexity. For most recreational boats in well-maintained marinas, a galvanic isolator provides excellent protection at a fraction of the cost.

Will this work with my inverter/charger setup?
Yes. The Victron Galvanic Isolator is fully compatible with Victron MultiPlus and MultiPlus-II inverter/chargers, as well as any other shore power system. It is installed on the ground conductor before the inverter/charger and all other AC equipment.

Do I still need zinc anodes if I install a galvanic isolator?
Yes. Zinc anodes protect against corrosion from sources other than shore power, such as dissimilar metals on your own boat and stray currents in the water. A galvanic isolator and properly maintained anodes work together as complementary layers of protection.

How do I know which size I need?
Match the isolator's amperage rating to your shore power inlet. If you have a standard 30A shore power connection, the VDI-32 is the right choice. For 50A service or dual 30A inlets, go with the VDI-64.

What's in the Box

• Victron Galvanic Isolator (VDI-16, VDI-32, or VDI-64)
• Mounting hardware
• Installation manual

Blue Marine is an authorized Victron Energy dealer — ships brand-new with the full 5-year Victron warranty, free shipping, and local pickup available.