News Flash

New Solution for On-Line Transformer Moisture Management Now in Test Phase

New On-Line Dehydration System’s Local Control Panel

September 17, 2010 – In our ongoing efforts to provide cost-effective customer solutions, Waukesha Service recently partnered with an equipment manufacturer to develop a system that removes moisture from oil and insulation systems while a transformer is energized. This new equipment will reduce the costly challenges of installing a mobile substation or extended outages associated with other moisture reduction methods, thereby helping minimize the impact on utilities’ customers.

Elevated moisture content is one of the leading contributors of accelerating loss of life attributes in working transformers. Diligent factory processing alone will not keep moisture from accumulating in the field. Increasing moisture levels can result in a significant reduction of expected life, lower the dielectric withstand capability of the insulation system and increase the insulation’s power factor (all combined this means the insulation’s electrical characteristics will break down faster than what is typical without moisture). Excessive moisture inside a transformer can also limit its capability to safely handle an overload situation when required. In spite of the dangers, many moisture issues have not been addressed due in large part to the cost involved and time required to de-energize and dry out the affected units. A number of situations also exist where transformers simply cannot be taken out of service because of the need to support an existing customer load. The recently developed Waukesha online dehydration system solves these problems.

After initial set up, the new dry out equipment is monitored and controlled remotely through a satellite communication system. While oil can be dehumidified quickly, diffusion of moisture from the insulation system through the oil may take several weeks—or months. This remote monitoring and tracking capability serves to validate the achievement of desired results prior to finalizing the drying process. Once complete, the oil dehumidification equipment can be disconnected and moved to another unit.

With a power requirement limited to 240V, 60A single phase, the equipment should operate well in most substation environments without requiring a new power supply. Additionally, the system includes an automatic shutoff to help prevent damage to the transformer or environmental release of oil in the event of power loss or operational limits being met.

The service group is currently conducting performance testing of the new equipment on customer sites to validate its performance, and they anticipate commercial lease availability by the beginning of 2011. In the meantime, Waukesha offers several other solutions to help reduce and control moisture in a transformer, including regasketing, dehydrating breather system installations and retrofits, FR3 retrofills and off-line field dry outs with hot oil vacuum purification units.


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