Protests over the D.C. police department's installation of a recorded message on its 911 emergency line asking callers to wait in turn for a dispatcher led police and city officials yesterday to unveil a new emergency telephone answering system they had hoped to keep secret longer.

Police officials also said the recording had been temporarily disconnected because of a "significant number" of calls by curious or angry residents, but will be reactivated this weekend.

At a news conference at police headquarters, City Administrator Thomas M. Downs said announcement of the new $1.5 million "state of the art" system had been delayed because of the experience of other cities that have made new 911 systems public. In other cities, he said, the announcement has prompted floods of calls from people who want to try the new operation.

Downs said he wanted to avoid that kind of surge during the shakedown period of the new 911 system here.

"I wanted to make sure that we had everything absolutely nailed down tight as a drum," he said.

A key feature of the new emergency setup, called Enhanced 911, is that a caller's telephone number and address automatically appear on a computer screen in front of the dispatcher handling the call, allowing authorities to follow up if the call is interrupted or the caller cannot give the location.

Assistant Chief William Dixon, who is supervising installation of the new system, took several dozen reporters and photographers through the communications area to explain the function of the recording.

"If all the screening positions are busy when a call rings, the call is automatically put in queue," he said. "At this point the caller can get a recorded message . . . . It is these features which were being tested over the past few days."

City Council Chairman David A. Clarke said, however, that he disapproves -- and will continue to disapprove. "I don't care how advanced or how rudimentary the system is, I don't want anyone getting a tape recording when they call," Clarke said.

Downs said the tape is played when a police operator does not answer the phone after a second ring. In calls to the 911 number made by The Washington Post on Wednesday and Thursday, the phone rang up to six times before the tape was played.

"It is impossible to answer every call on the first or second ring," Downs said. "It is a failsafe device to ensure first that the call is answered . . . . There is the reassurance that they are there, and our response time so far is 12 seconds even with the recording."

Downs added, "I would feel more comfortable knowing that I had the right number than waiting for the third ring. It's a judgment call as to whether or not you'd rather wait for the third ring and wonder whether or not you have the 911 system."

Gary Hankins, labor committee chairman for the Fraternal Order of Police, yesterday disputed Downs' assertion that the use of the recording does not indicate a lack of personnel.

"There are not enough qualified people to answer the calls," Hankins said. "The ideas are great, but if you don't have enough people to answer the phones, you will pay for it later."