More than 8,000 McGraw OA-3 and 6,000 McGraw OA-4 mechanisms have been sold internationally. As a result, the demand for parts and service of these devices is still active.

“Budget cuts and restructuring of power utilities have reduced preventative maintenance practices and much of the experienced utility personnel have since retired with the knowledge of these mechanisms,” said James Rigdon of.Pennsylvania Transformer.

Rigdon will present Maintaining McGraw-Edison OA-3 and OA-4 Mechanisms on Thursday, Oct. 8, at the 2009 Finepoint Circuit Breaker Test and Maintenance Training Conference.

“Since these mechanisms are no longer manufactured, parts and labor can be difficult to obtain. Pennsylvania Transformer has a stock of many of the parts commonly replaced in the field,” Rigdon said. “It is our goal to share with customers some general knowledge, common problems, and maintenance practices for the OA-3 and OA-4 type mechanisms.”

In 1952, Pennsylvania Transformer became a division of McGraw Electric Co. In 1957 McGraw Electric Co. merged with Thomas A. Edison Company to create McGraw/Edison Co. Since then, Pennsylvania Transformer has offered original equipment replacement parts and technical assistance for McGraw/Edison, Federal Pacific, and Cooper-type mechanisms and breakers.

Rigdon has worked with Pennsylvania Transformer Technology since 2006, providing service for oil, vacuum, and SF6 circuit breakers ranging from 15 kV-242 kV. His experience also includes building and field service for 230 kV gas circuit breakers at Pennsylvania Breaker. Prior to PA Breaker, he worked with Alston T&D (now Areva) as a production builder and team leader for SF6 gas breakers, ranging from 72 kV to 230 kV.

Visit Pennsylvania Breaker at the Hospitality Expo in Booth #10.