Marine Isolation Transformers

Energy Solutions offer single and three phase Isolation Transformers of all capacities. Our standard range of Isolation Transformers have the following features. 

Complete range - Our standard transformer range covers 10, 16, 32, 50, 63 & 100 amp single phase shore capacities at 230v.

Voltage conversion models - We offer a 63 amp transformer that selects between two input tappings with 208 volt and 240 nominals - ideal for USA spec boats looking for an alternative to the Charles Industries Iso-Boost.

Dedicated output - Our larger transformers come configured to provide either 120 - 0 - 120v 4 wire USA output or 0 - 230v 3 wire Euro output. ABYC compliant. All transformers are built with a screen between primary and secondary windings capable of carrying twice the full load current of the transformer. This exceeds the requirements of ABYC E-8.20.1 by 100%.

Lloyds compliant - All transformers are built to comply with the requirements of LRS.

Resin coated - The transformers are protected with a UL approved vacuum impregnated polyester varnish.

Background

Bringing shorepower onto a yacht or ship offers a great deal of convenience for the owner. But it can also lead to galvanic corrosion and other problems. Good engineering practice, Lloyds rules and the Recreational Craft Directive all call for an on-board AC earth system to be bonded through to the sea. On a metal-hulled boat this is done by taking the earth to the hull, on other craft it is via a specific ‘grounding’ plate. In making this important safety connection you create a galvanic loop which can accelerate corrosion of the boat.

The symptoms

On metal-hulled boats galvanic corrosion can cause general hull corrosion as well as localised pitting - especially along the waterline. Sometimes this pitting and corrosion is localised - perhaps close to shore based metal objects. This corrosion of the hull happens despite the fitting of anodes. The ships’ anodes also tend to corrode at an accelerated rate. On non-metallic hulls anodes corrode at an accelerated rate and underwater metal fittings can experience corrosion despite the fitting of anodes.

The Solution

A hull isolation transformer breaks the earth wire on the incoming shorepower. The primary (input) side of the transformer induces a voltage on the secondary (output) side. This is done with no physical connection between the shore cable and the on-board wiring - they are completely isolated from each other.

The output side can then be configured to suit the electrical system on the vessel. For UK built boats this usually means that the output neutral is bonded to earth. This allows the use of single pole circuit breakers and switches.

The boat gets its earth protection from the sea via the hull or groundplate, but no circuit is formed, as the shorepower earth is not connected.

Custom Transformers

If your needs aren’t covered here don’t worry. We can supply a transformer to meet your specific requirements.  This may be three phase delta to three phase delta or star, three phase delta to single phase or split phase or maybe a transformer to take power from two phases of a ships three phase delta supply to provide single phase at the correct voltage.

We also supply autotransformers for applications where voltage conversion, but no isolation is required.