Jon J. Kark, 62, engineering department manager of the National Electrical Manufacturers Association (NEMA), died Saturday in a hospital in Warwick, R.I., after a heart attack. He was vacationing in Rhode Island when he was stricken.

He joined NEMA as an engineer in 1952, became assistant manager of the engineering department in 1974, and was promoted to department manager in January of this year.

Mr. Kark was a native of New York City and lived in New Jersey before coming to Falls Church in 1977 when NEMA transferred its headquarters from New York to Washington. He earned a bachelor's degree at the Newark College of Engineering.

He was a member of St. James Catholic Church in Falls Church and the Edward Douglas White chapter No. 2473 of the Knights of Columbus. His professional memberships included the Institute of Electrical and Electronics Engineers, and the International Association of Electrical Inspectors. He also was a member of the National Fire Protection Association.

Survivors include his wife, Anna, and a son, Jon J. Jr., both of Falls Church; two daughters, Joanne Kark of Knoxville, Tenn., and Nancy Bennett of Exeter, R.I.; a sister, Valerie Gelcius of Kearny, N.J., and one grandchild.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association.