The three-part U.S.-Soviet negotiations on nuclear and space arms that began Tuesday in Geneva have required the Arms Control and Disarmament Agency to set up the most extensive backup system in its 23-year history.

Each of the three negotiating areas -- space and defense arms, strategic nuclear arms and intermediate-range nuclear forces in Europe -- has a negotiating team of about 10 officials from various U.S. agencies, headed by prominent ambassadors as chief negotiators.

Supporting them are about 30 full-time ACDA staff members in Geneva and another 20 in Washington, according to ACDA Director Kenneth L. Adelman. This is in addition to a corps of 10 to 12 Russian-language interpreters and an assortment of personnel from other agencies who are in Geneva.

To support the negotiations, Adelman said, ACDA has installed eight word processors and eight secure telephone lines, compared with the two word processors and two phone lines in place during earlier negotiations. To allow participants to wine and dine their Soviet counterparts -- not to mention the members of Congress who look in on the talks -- this year's representation allowance has been set at $27,000, about three times the amount previously available.

Chief of the overall U.S. delegation is Washington attorney Max M. Kampelman. His deputy is Warren Zimmerman, formerly deputy chief of the U.S. Embassy in Moscow.

Kampelman's deputy for the space and defense negotiations, which he also heads, is Henry Cooper, chief of ACDA's Strategic Programs Branch.

Ronald Lehman of the National Security Council staff is deputy to former senator John G. Tower (R-Tex.), chief negotiator for strategic arms.

Career diplomat Maynard W. Glitman, chief negotiator on intermediate arms, is being assisted by John Woodworth of the Defense Department.

In Washington, Louis Nosenzo heads the backup team for the whole delegation and for the space talks. Victor Alessi leads the backup team for strategic arms; R. Lucas Fischer, intermediate arms. All three are ACDA officials. These teams will process instructions to the negotiators when changes or details are needed beyond the general instructions given last week by President Reagan.

A backup team for the Standing Consultative Group, in which the two nations will discuss compliance, is headed by James Milner.

Interagency groups -- including representatives of the CIA, White House, ACDA, DOD and State -- will provide yet another backstop. Nosenzo heads the group for space and defense and Lt. Gen. John T. Chain Jr., head of the State Department's Bureau of Politico-Military Affairs, heads the group for strategic and intermediate-arms issues.

Finally, two ACDA archivists have been assigned to Geneva to gather and maintain a historical record. In recent years, the agency has computerized the statements made in confidential arms talks and related discussions. This record makes it possible for today's U.S. negotiators to determine quickly what has been said before by either side on the subjects at hand.

In a sense, it is the U.S. substitute for the much greater arms negotiating experience and institutional memory of the negotiators on the Soviet side.