Galvanic Isolators Compared: 16A to 64A
We carry galvanic isolators from 16A up to 64A across three brands — ProMariner, Victron Energy, and a generic budget option. A galvanic isolator blocks stray DC current from flowing through your shore power ground wire, which is what causes electrolytic corrosion to underwater metal — hull, propeller, shaft — while still passing full AC safety fault current if there's ever a short on board. Amp rating needs to match or safely exceed your shore power service; beyond that, brand mostly comes down to certification and price.
- Amp rating must match (or safely exceed) your shore power service — 16A, 30A, 32A, 50A, or 60/64A
- ProMariner's ProSafe FailSafe line is ABYC A-28 compliant and UL certified
- Victron and the generic DE-Coupler units cover similar amp tiers at a lower price point
- Only one isolator is needed per boat, sized to your largest shore power connection
ProMariner’s ProSafe FailSafe isolators (the 22034 and 22074) are explicitly ABYC A-28 compliant and UL certified per the manufacturer’s own listing — the only lineup here with that specific certification called out. Victron Energy and the generic DE-Coupler units aren’t documented either way in their own listings, so if certification matters for a survey or insurance requirement, verify directly with the manufacturer before ordering rather than assuming.
Our lineup at a glance
What amp rating do I need?
Match it to your shore power service — a 30A shore connection needs at least a 30A isolator, a 50A connection needs at least 50A, and so on. A higher-rated isolator is safe to use on a lower-amp connection; going the other way is not.
Is a galvanic isolator required by ABYC?
ABYC A-28 is the standard that covers galvanic isolators, and many marinas and insurers expect boats to have one installed on their shore power ground. If certification specifically matters for your survey or policy, the ProMariner ProSafe FailSafe units are the ones in this lineup with ABYC A-28 compliance and UL certification stated directly by the manufacturer.
Can I use a lower-amp isolator than my shore power service?
No — size the isolator to at least match your shore power service’s amp rating. An undersized isolator can be a fire/overload risk under full load.
Do I need more than one isolator for two shore power connections?
Not necessarily — if both connections share a single AC ground bus, one isolator sized to the combined or larger connection can cover both. Check your boat’s wiring before assuming you need two.
Bottom line
Size the isolator to your shore power service first, then decide on brand. If ABYC A-28 certification matters for a survey or insurance requirement, ProMariner’s ProSafe FailSafe line (22034 at 30A, 22074 at 50/60A) is the documented choice here. Victron Energy covers the widest range of amp tiers (16A, 32A, 64A) at a mid-range price. The generic DE-Coupler units (30A, 50A) are the lowest-cost option at their respective amp tiers.
