The nation's biggest and most politically controversial pay raise, a $2.7 billion package covering several million government and military personnel, clicked into effect quietly at 12:01 yesterday morning.

When announced by the president, the 5.5 percent federal-military pay hike triggered threats of strikes and slowdowns from government unions who thought it too little. It also brought warnings of a new taxpayer revolt from private citizens and politicians who think it too much.

When fully effective, the 5.5 percent pay raise will bring the before-taxes salary of the average white collar Washington civil servant to $22,000 a year. For federal workers away from Washington's higher-grade headquarters pay structure, the boost will bring average salaries up to $18,500, according to official government pay data.

More than 409,000 people in the Washington area will feel direct results of the pay raise, either in civilian salary checks or in military pay. Most other Washington residents - whether they work for government or not - will also notice it as parking fees, food prices, rents and other basic items are adjusted upward in our bureaucracy-oriented economy.

The bulk of the $2.7 billion payroll rise will go to military personnel. Retired federal workers and postal employes are not included in this pay raise. Nor are blue collar (wage board) workers.

President Carter decided on the 5.5 percent raise even though government salary data comparing pay gains in the private sector indicated a catchup-with-industry raise of around 8.4 percent was justified. Since the government makes that survey, many people believe it is off the mark - either too high or too low, depending on one's views of federal salaries.

Carter acknowledged that the raise is too low, but said the government has to make the first financial sacrifices if it is to persuade labor and management in the private sector to adopt voluntary wage-price restraints. Federal union leaders say Carter is following in the footsteps of his predecessors - both Democrats and Republicans - in making white collar government employes and the military the scapegoats and guinea pigs for half-hearted inflation-stopping experiments.

The pay raise for the typical Grade 4 clerical federal worker on the job for several years will amount to $537 a year. For a beginning management trainee at GS 7 the boost will be $747 and for mid-level Grade 15 managers it will be worth $2,187 per year. Employes making $47,500 or more will not get any increases.

Congress and the White House decided to freeze federal career salaries at the level, although members of Congress allowed themselves $12,900 raises last year and White Hoouse staff pay jumped dramatically after Carter took office.

Under the law designed to keep federal pay current with industry levels (as determined by the government) Congress could have vetoed the 5.5 percent limit, and ordered full 8.4 percent catch-up raises for civil servants. But that subject is so contoversial just one month before the elections that Washington area members of Congress feared to put the issue to a vote.

Rep. Herbert Harris (D-Va.), original backer of the resolution to give a full 8.4 percent raise to government workers decided against bringing the matter before the House. Harris figured that it would be used as an anti-government launching pad for fellow members who don't have many government workers in their districts.

The raise actually went into effect Oct. 1 for military personnel. White collar civilians will get it with the first pay period beginning on or after October 1. Most will not see results of the new raise for several weeks yet.

Are They or Aren't They? For years the Defense Department has had a split personality over the federal status of thousands of nonappropriated fund (NAF) workers. They are employes of PXs, commissaries, canteens and other service support activities.

When the new law eliminating the mandatory retirement age of 70 for federal workers was passed, Defense decided it would not apply to NAF personnel. But Rep. Gladys N. Spellman (D-Md.) who wrote the bill, said it should, and asked the General Accounting Office for a ruling. GAO has come up with a ruling (B-165430) that says the no-age retirement policy also covers NAF workers.