Carroll D. Buracker, who earned a reputation as an ally of the beat officer while serving as deputy chief of the Fairfax County Police, yesterday was named head of the 720-member force that covers one of the largest and most divergent jurisdictions in Northern Virginia.

Buracker, a 15-year veteran of the county force, said in an interview that his major effort as chief will be to "try and motivate the troops."

The force has become so large and is spread over such a large area that the individual officer has to be reminded he is not forgotten, the 39-year-old Buracker said.

"We're getting college graduates, employes that are highly charged and motivated. We need to keep that level high, let them know how they're going to be recognized when they do a good job."

Buracker's selection by the Board of County Supervisors yesterday was not a surprise. He long had been considered a front-runner for the position and became acting chief on May 11, when then-chief Richard A. King was promoted to a newly created post of deputy county executive for public safety.

With his promotion Buracker, a slight, pain-talking Virginia native, will receive a $4,576 raise to $50,931 a year and will have the rank of colonel.

Like his predecessor King, Buracker is a staunch defender of his department. He dismisses recent news accounts about allegations of excessive force by county police and of troubles in the police communications center as inaccurate and having been "taken out of context."

And, like King -- who is credited by many with deflecting pressure for a civilian police review board by creating citizen advisory commissions with limited powers -- Buracker said he believes that the business of law enforcement should be handled by police professionals.

County residents "should have input into policy and procedures, but . . . by definition, police officials have had a lot more experience in running a department properly," said Buracker, who played a major role in developing the department's community and press relations section.

Although Buracker said he plans to "carry on the fine traditions of this department," police officials and members of the rank and file said that the difference in style between King and Buracker could set a different tone for the department.

In his seven years as chief, King earned a reputation as a skilled and effective administrator. Yet, in keeping with his military bearing, King held fast to traditional ideas of chain of-command, choosing to disseminate and receive information through his deputies. "To the typical officer, the word remote might be applicable," said one longtime police official. "King is not a household word to the men on the street. . . . I can't remember a single crime scene I've seen him on."

Buracker is highly regarded on the force as a policeman's policeman. Said county police association chief Ralph T. Widmer: "Buracker's there if you ever need him. . . . Anyone willing to come out and visit a substation as he does has the men in mind and will have their support."

Buracker is most remembered for his efforts during the summer of 1979, when, after completing his own eight-hour work shifts as newly appointed deputy chief, he went out on the streets and rode along with the patrol officers five evenings a week for two months.

Following that experience, Buracker worked vigorously to bring about the department's four-day/10-hour shift system. Implemented in February, the system has police officers working four day weeks of 40 hours rather than the old seven days on, two days off system that police officers claimed made them overworked and inefficient.

"Carroll will probably be more active in trying to get for the troops what they need in doing the job," said Capt. Jerrel M. Daughtry. He described Buracker as "a hot shot . . . a man who just wouldn't quit until the job was done right."

Buracker grew up in Rileywille, Va., near Luray. After his mother died when he was a year old, Buracker went to live with an elderly couple. As a boy, he said, he walked several miles each dawn to a neighboring farm to milk the cows in exchange for spending money.

After two years as an Army military policeman, and another with the Harrisonburg, Va., police force, Buracker came to Fairfax in 1966, he said, "because in order to excel in my field I had to move to a larger agency."

Since then, he earned bachelor's and master's degrees in law enforcement at American University. He scored first on the department's exams for lieutenant, captain, major and deputy chief, and has published articles in major police trade magazines and been a consultant to several departments around the country.

In the county, Buracker has worked in capacities that range from patrol officer to detective to budget planner to media spokesman. He helped develop computerized systems to speed up vehicle and arrest warrant identification, a drug-enforcement program and several community-oriented programs that have attempted to involve police officers more with county residents.

A resident of Kings Park West who is married and has two young sons, Buracker said he believes he fits well into-a county that has, for the last 20 years, suffered growing pains.

The farmer from Bull Run, Buracker said, must be kept as happy as the federal bureaucrat who lives in Fairfax City. "With the 1980s here and the budgeting process being as it is, the dollar is becoming tighter, and citizens are expecting more from their bucks. We need a dedicated force to do this, and that's what we'll be working on."