The Advantages of Liquid-Filled Transformers Over Dry-Type Transformers

The Advantages of Liquid-Filled Transformers Over Dry-Type Transformers

What types of transformers is your company using in your day-to-day operations? Eaton released an informative study showcasing how beneficial liquid-filled transformers are over dry-type in a variety of ways.

We present five reasons you should consider switching from dry-type transformers to liquid-filled.

 

Greater Energy Efficiency

In terms of cost-effectiveness, evidence shows dry-type transformers have significantly higher operating costs.

 

Lower Sound Level

Sound pollution is an issue in many factories. Earplugs are recommended for many workers working near mills, construction sites or anywhere heavy machinery is operated. Sound pollution has been linked to poor health in humans and animals alike. Sleeping issues and cardiovascular issues have all been documented with excessive sound pollution. Any consistent noise over 60 decibels can cause lack of attention with prolonged exposure – the average factory and dry-type transformers usually hover near or above 64 – 70 decibels. Liquid-filled transformers can bring that number closer to between 58 – 63 decibels. On their own, that may not seem like a huge difference, however, sound pressure reportedly doubles for every 3-decibel increase! Now those numbers look significant!

 

Smaller Footprint

Dry-type transformers require more space which means higher size demand and greater use of available space. In some cases, dry-type can double the square footage needed over liquid-filled. Larger sizes require more room meaning more ventilation and operating costs. Have you examined the numbers regarding the footprint of your transformers?

 

Much Longer Operating Life, Ease of Maintainability and Repairability

On average, dry-type transformers need to be replaced before their liquid-filled counterparts. Dry-type usually last 14 and 25 years, whereas liquid-filled transformers can operate up to 35 years. Keep that in mind when planning for the long-term success of your projects and facilities.

Also, maintaining dry-type transformers requires extensive maintenance including inspecting, vacuuming and cleaning grills and coils. Failing to do this consistently and safely could increase the likelihood of a fire. Less flammable liquid-filled transformers only require a sample of the insulating oil to check the health of the transformer.

Keep this in mind when discussing the cost of maintenance:

 

2500kVA Transformer:

Liquid Cast Dry
Purchase Price $35,000 $60,000 $38,000
Operating Life (years) 35 30 25
Annual Maintenance none 6 hours, $360 6 hours, $360
Outage Required for Maintenance N/A Yes Yes
Fire Hazard if not Maintained: No Yes Yes
Repairable Yes No Yes
Annual cost to purchase and maintain $902 $1693 $1376

*Moran, Robert B. Guidelines for transformer application designs. Electrical Construction and Maintenance, May 1996

 

Ease of Recycling

Liquid-filled transformers can be easily recycled after their long, useful life. The transformer fluid can be reconditioned and used again, and the steel, copper, and aluminum can be completely and economically recycled, providing a positive cash flow.

Cast resin type transformers are an exception. Because of their construction, the materials in cast resin type transformers can be difficult and uneconomical to recycle. When a cast coil fails, the entire winding, encapsulated in epoxy resin, is rendered useless and typically ends up in a  landfill. This wastes the resource and creates additional costs for disposal, plus long-term liability exposure to the original owner.

If you would like to learn more about how Eaton, EMR Associates, and liquid-filled transformers can help you, get in touch with Mike Hughes or call at 615-828-8028.

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