DEI Marine Galvanic Isolator 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.

A key feature of DEI's approach is the assured safety grounding of the boat under all conditions. This important feature, a fail-safe design, provides assured safety grounding even in the rare event of product failure. The 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) makes provision for a fail-safe GI that will not require monitoring, as it assures safety grounding under all conditions. The DEI fail-safe design avoids the nuisance issue of the monitoring system, which has been troublesome for boat builders and users alike. 

Additional advantages over other isolators include much higher AC fault ratings, ratings for lightning surge current (not even required in the standard), cool operation, 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:

DEI has many years of experience designing, manufacturing, and testing electrical products for electrical generation, transmission and distribution systems, as well as low voltage industrial systems. If power utilities can trust us to protect their largest generator step-up power transformers at a power generating plant, you can also be assured of solid product designs for boat grounding. Our engineers will gladly assist any customer with the proper rating and selection of a Marine Galvanic Isolator.
Elimination of all customer calls pertaining to "monitor alarms"
Extensive experience in providing fail-safe products to the corrosion prevention industry