Trans-Rupter II® Model SE: A Permanent Solution for a Temporary Substation.

An electric utility in the Midwest needed to provide service to an ethanol plant under construction. A 20-MVA mobile substation had been in place at the site for over six months. But the utility didn’t want to leave it there for the two years in which they were responsible for providing service. So they decided to build a temporary substation. Waukesha Electric Systems, the transformer manufacturer, mounted a 138-kV Trans-Rupter II® Transformer Protector Model SE directly on the 138- to 12-kV, 10/12-MVA transformer, along with a disconnect switch. The control cabinet was custom-installed directly on the side of the transformer, and the entire installation mounted to railroad ties. The mobile unit will be moved by rail to another location after construction at the plant has been completed, and a permanent substation is constructed.

The Trans-Rupter II Model SE was particularly well-suited to this installation because of its lightweight construction, and ability to be applied in situations where no control power is present — the Model SE relays are powered by the transformer’s internal current transformers.