Comdial Corp. has named Ronald C. Whigham, a former general manager of Westinghouse Electric Corp.'s electronic components manufacturing business, to the post of president of this Charlottesville-based maker of business and residential phone systems.

Brought to the firm as executive vice president last November, Whigham, 53, has directed much of the company's efforts in recent months to pare down manufacturing operations and stem the losses that have plagued Comdial for the last 1 1/2 years.

A longtime Westinghouse executive with general management experience, most recently in manufacturing semiconductors and cathode ray tubes, Whigham has brought "a fresh outlook on manufacturing approaches," a spokesman said.

In a move widely expected by the company's management, Ted B. Westfall, 65, chairman and chief executive officer, will relinquish responsibility for the firm's daily operations to Whigham and concentrate on strategic planning and marketing, Whigham said.

Westfall had held the title of president since Comdial founder and former president Don Hoff resigned to pursue other business interests more than two years ago, a spokesman said. Comdial, the country's fourth-largest telephone manufacturer with $125.1 million in sales last year, still is recovering from the loss of its principal marketing channels to American Telephone & Telegraph Co. in 1983 and the ensuing costs of repositioning itself in the marketplace.

But Whigham believes that the company's realignment, which has meant layoffs and consolidating plant operations, is drawing to a close and that its earnings will continue to improve through sales of new products.

"The business has bottomed out," Whigham said, emphasizing that the last 1 1/2 years of losses can only improve. Comdial recently reported a loss of $8.4 million for the first six months of this year, much improved over the $20.4 million loss posted for the same period in 1984.