Technological Comparisons

Comparison of DEI Galvanic Isolator (GI) to other industry galvanic isolators

DEI manufactures Galvanic Isolator models to a higher level of performance because we recognize the safety and liability implications due to inadequate grounding from our experience with similar products in the energy industry. DEI brings this experience to the marine industry by offering a much more complete and conservative approach to boat grounding and galvanic isolation.

DEI is responsible for introducing fail-safe design characteristics to the marine industry.  Fail-safe design is essential for safety and required for any shore-based application which comes under the U.S. National Electrical Code (NEC).  The most recent revision of ABYC A-28 (July 2008 publication) also makes provision for a fail-safe GI that will not require monitoring, as it assures safety grounding under all conditions. A major benefit to the fail-safe design approach is eliminating nuisance alarms from often faulty monitoring systems.

Additional advantages over other isolators include much higher AC fault ratings, making the product more reliable, ratings for lightning surge current which are not offered by others, cool operation which allows the product to be fully sealed, and robust construction.

Comparison of DEI Galvanic Isolator (GI) vs. Isolation Transformers

DEI offers the Galvanic Isolator to the marine market as an alternative to isolation transformers. Where voltage or frequency conversion on the boat (from shore power) is not required, the Galvanic Isolator offers a lower cost option to obtain isolation.

The size and weight of a DEI Galvanic Isolator is significantly less than an isolation transformer. DEI's Galvanic Isolators range in weight from 3.5 to 13 pounds (1.6 to 6 kg) and are a small fraction of the size of any isolation transformer.

Polarization Transformers

Even where an isolation transformer is installed, a Galvanic Isolator is beneficial, by keeping the boat hull and grounding system referenced to shore ground.  By converting the isolation transformer to a polarization transformer arrangement, a fault from the primary phase to the transformer enclosure can be conducted through the galvanic isolator, avoiding injection of fault current into the water, which has significant safety implications.

Other Benefits:

  • Extensive experience in fail-safe isolation products
  • Eliminates nuisance alarms
  • Assured safety grounding under all product conditions