An offshore platform is a harder installation than a ship in one specific way: maintenance visits are expensive and infrequent, so the equipment has to be built for a longer interval between interventions.
What makes offshore different
- Atmosphere. Continuous salt spray and high humidity, with no shelter. Corrosion protection is specified rather than assumed.
- Vibration. Drilling, compression and pumping machinery run continuously and load the structure throughout.
- Hazardous areas. Where hydrocarbons are present, equipment certification has to match the zone classification of the space it sits in.
- Access. A maintenance visit may involve a helicopter or a vessel. Designs lean towards arrangements that need less frequent attention.
- Weight and footprint. Deck space and structural loading are both constrained, which pushes back on the additional steel that corrosion allowance and enclosure ratings add.
Types used offshore
- Dry type and cast resin transformers are the common choice for the same reason as on board: no oil means no fire load and no containment requirement. Cast resin additionally seals the windings against salt air.
- Isolation transformers where galvanic separation is required between systems.
- Step-up transformers for power export from offshore wind substations, which is a different duty from platform distribution and is specified separately.
- Special purpose units for drilling drives and similar loads.
Where they are used on a platform
- Main power distribution and switchboard supplies.
- Drilling equipment and top drive supplies.
- Production and process equipment.
- Compression and pumping systems.
- HVAC and ventilation.
- Communication and navigation equipment.
- Accommodation and living quarters.
- Cranes and material handling.
- Export supply from offshore wind substations.
Maintenance interval is a design input
On shore, a problem can be attended to in a day. Offshore, it may wait weeks. That changes what is worth specifying: heavier corrosion allowance, sealed enclosures, corrosion-resistant fixings, and monitoring that can be read remotely rather than requiring a visit. The temperature monitoring and insulation resistance checks that would be routine on shore become the main early-warning tools when access is limited.
If you are specifying for an offshore installation, send the zone classification, the ambient conditions and the space available alongside the electrical ratings. See the offshore transformer range, or contact us.
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How this is packaged on real projects
On most sites the unit described here is not installed on its own. It goes into an assembly that includes the incoming switching, protection and outgoing feeders, which you can see on the oil and gas electrical distribution, MV switchgear and compact substations pages.
Frequently Asked Questions
What should be confirmed before ordering a transformer for an offshore platform?
System voltage and frequency, fault level at the point of connection, the load with its duty, and the site conditions including ambient range and indoor or outdoor placement. With those settled the rest of the specification follows.
What makes a marine transformer different from an ordinary one?
The construction around the transformer, not the electrical function. Continuous vibration, salt-laden air, confined spaces and the classification society approval route all shape the design. Vibration-resistant core clamping, corrosion protection and the documentation package matter as much as the rating.
Which classification approvals are needed?
It depends on the flag state and the class society the vessel or platform is registered under. Approval requirements are confirmed against your project before production rather than assumed, and the documentation package is assembled to the route your project follows.
Which standard applies, and is it certified?
The applicable standard and clause set are agreed against your project specification before production starts. Where a project names IEC 60076 for the transformer, we work to those clauses and the routine test report ships with the unit.
What do you need from us to quote?
The single-line diagram or a description of the application, the voltages, the load with its duty, the site conditions, and any standard the project specifies. Send what you have – if something is missing, it can be worked out together rather than delaying the enquiry.