The chairman of the Consumer Product Safety Commission, in an action that has drawn sharp protests from consumer groups, members of Congress and his two fellow commissioners, has stripped the agency's compliance director of authority to enforce the agency's existing safety rules.

CPSC Chairman Terrence M. Scanlon acted on his own to reassign David Schmeltzer, the agency's longtime chief of compliance, to a special project, describing the transfer as a temporary response to "serious management problems," officials disclosed yesterday.

The action reopened a bitter feud between Scanlon, a controversial Democrat appointed by President Reagan, and the two Republicans on the three-member commission and renewed charges from Scanlon's critics that he wants to make the agency ineffective.

". . . I must conclude that this is yet another attempt to intimidate the staff, censor the free flow of information and prevent the commission from fulfilling its public trust," Commissioner Anne Graham wrote in a sharply-worded three-page memo to Scanlon. "If your objective is to paralyze the commission, you are succeeding."

"In my opinion, it's a move that will tragically cripple the last spark of life in that agency," said David Pittle, a Democrat who served on the commission for nine years and a longtime critic of Scanlon. "The compliance effort is one of the remaining strong points of that agency."

Schmeltzer's supporters yesterday praised him as one of the last division heads at the agency willing to publicly fight Scanlon's efforts to reduce the commission's role. They said Schmeltzer is unwilling to accept Scanlon's desire to settle product safety disputes on the basis of voluntary action by industry.

"I feel like a pawn in this," Schmeltzer said yesterday. "I don't know why I was reassigned. I don't know."

The Scanlon critics said that by replacing Schmeltzer with Douglas Nobel, a nonlawyer who heads the agency's voluntary compliance section, Scanlon was telling industry that the agency will be less aggressive.

Reps. James J. Florio (D-N.J.) and Dennis E. Eckart (D-Ohio), members of the consumer protection subcommittee of the House Energy and Commerce Committee, also voiced objections in a letter to Scanlon yesterday and demanded to know why Schmeltzer was transferred. "This is the latest in a series of personnel changes which have had the effect of weakening the CPSC's role of insuring product safety," they said.

Scanlon was vacationing yesterday and could not be reached for comment. A spokesman released a two-paragraph memo Scanlon sent Graham in which he accused her of failing to understand the seriousness of the agency's management problems.

"You may not want to admit these problems exist, but to paraphase two other Irishmen, I am not going to stand by and be a potted plant when they come to my attention," Scanlon said.

A aide to Commissioner Carol Dawson said Dawson sided with Graham and did not believe there was "any basis" for Schmeltzer's reassignment. ". . . You've got to be kidding!," Dawson wrote Scanlon in a memo yesterday.

The 14-year-old CPSC has shrunk dramatically under the Reagan administration, and the major enforcement actions that once were its hallmark have become infrequent. Its budget has fallen by more than 30 percent, and it has not issued a final product safety rule since 1984. Final safety rules are a prime index of the commission's activity.

During congressional hearings this summer, the agency, and Scanlon in particular, were attacked for failing to address such issues as the safety of all-terrain vehicles, disposable lighters and lawn dart toys. The administration also has signaled its unhappiness with the CPSC by calling for its abolition as an independent agency and its merger into the Department of Health and Human Services.

As recently as last Thursday, Schmeltzer, who has been employed by the agency for 11 years, was reportedly at odds with Scanlon for urging the three-member commission to move against lawn darts. Schmeltzer cited the congressional testimony of a California parent whose child was killed when one of the metal-tipped lawn toys struck the child's head. Scanlon objected to the way the compliance section had acted on that case and others and was troubled that he could not get answers to some of his questions, an aide said.

Schmeltzer, who has served under both Democratic and Republican administrations, was praised by Mary Ellen Fise, product safety director of the Consumer Federation of America as "the one senior executive at the commission who is pro-consumer, who is carrying out the mission of the agency."

Fise called Schmeltzer's reassignment part of a "personnel chess game" that will lead to reassignment of key personnel in three of the commission's major divisions. Such transfers have become so frequent that they are "a great excuse for not doing anything. You're always trying to find out what your job is," Fise said.

Schmeltzer's section is "the core of the commission," Graham charged in her memo to Scanlon. "Yet, you and the executive director {Leonard DeFiore, a Scanlon appointee} have seized every opportunity to undermine the effectiveness of the directorate, which . . . has the most casework of any directorate in the commission."

Specifically, Graham accused Scanlon and DeFiore of refusing to allow promotions and vacancies to be filled in the section and of reassigning staff from the section, including Schmeltzer's own special assistant.

Graham also blamed Scanlon for blocking action on all-terrain vehicles, the off-the-road motorized vehicles that the commission previously declared an "imminent hazard."