Sixteen House committee chairmen have sent a letter to Speaker Thomas P. (Tip) O'Neill Jr., protesting the House Budget Committee's efforts to impose spending restraints on them.

The new congressional budget process provides for adoption of two budget resolutions each year. The first, adopted in the spring, traditionally has set targets for spending ceilings. The second, in the fall, has set binding ceilings Congress must live within.

But this year, in an effort to force movement toward a balanced budget, the Budget Committee inserted a provision in the first resolution to force committees to abide by spending ceilings as soon as the first resolution is adopted next month. Reconciliation, it is called.

Several committee chairmen, including Reps. Jamie Whitten (D-Miss.) of Appropriations, Morris Udall (D-Ariz.) of Interior and Insular Affairs and Carl Perkins (D-Ky.) of Education and Labor protested that the action usurps the jurisdiction of their committees. Their letter to O'Neill asks that he help see to it that when the Rules Committee sends the budget resolution to the House floor, an amendment will be permitted to knock out the reconciliation section.

One chairman who didn't sign the letter was Thomas Foley (D-Wash.) of Agriculture. He said he might have signed such a letter last year, but he now thinks balancing the budget is so important that reconciliation is justified.