Senate debate on a new code of ethics opens today with controversy growing around proposals that would limit a member's outside earned income.

Like a version recently approved by the House, the proposed Senate code provided for extensive disclosure of income and gifts by members and top staff aides. It also limits any outside earned income to 15 per cent of a senator's salary. That would be $8,514 under the present $57,500 scale. The drafted code provides no limit on a member's investment income.

Yesterday, a bipartisan group of senators led by Sen. Edmund S. Muskie (D-Maine) circulated a proposal which they said would achieve "a common code of conduct equitably applicable to all."

Two alternative amendments: one would apply the 15 percent limit to the other would strike entirely the both investment and earned income; presently proposed earned income limit language leaving the code with only disclosure for a member's outside income, both earned and investment.

An aide to Sen. Gaylorrd Nelson (D-Wis.), who chaired the special committee that drafted the proposed code, said yesterday that the Muskie proposal "seemed to be gathering some support."

He argued against it, however, saying "if a senator comes to the body wealth there is not a great deal you can do about it; but if he comes without wealth and engages in personal services to become wealthy, that is a different case."

Sen. Bob Packwood (R-Ore.), a member of Nelson's special committee was one of the co-sponsors of the Muski proposal. Packwood said yesterday that he believes "there is starting to be a reaction against some provisions of the draft code."

Debate on the code is now expected to last longer than originally expected. Some proponents of the measure had hoped to have it concluded by Friday.

A time agreement, however, between Majority Leader Robert C. Byrd (D-W. Va.) and Minority Leader Howard H. Baker (R-Tenn.) will allow 50 hours of debate and thus carry discussions well into next week.

Byrd said yesterday he expects a "strong code" to be approved.

On the outside income controversy, Byrd said, "I hope we can maintain the 15 per cent limitation" on earned income, though he added, "personally I favor no outside earned income at all."

Byrd said he believed members who make speeches for Honoraria or follow other employment away from the Senate are limiting the amount of time they have for legislative work.

Baker, however, in a recent interview said he thought the ethics code was "headed in the wrong direction."With the income limitations, Baker said, "we will become professional legislators directly and solely dependent on federal salaries."

Packwood, in an interview yesterday, put it more sharply. "The ethics limitations are a nose under the tent," the Oregon senator said.

With the addition of federal financing of Senate elections, Packwood said, "we will become full-time elected bureaucrats, publicly kept at taxpayer expense."

Packwood heatedly added that reformers would next require that "we log every phone call, and note every one we see, making us total political eunuchs."

Both Baker and Packwood plan to argue that senators spend less rather than more time in Washington and that the idea of full-time legislation was wrong.

Baker said he wanted to see Congress go back to sessions of six to eight months at reduced salaries" andthat members spent more time at home with their constituents.

Another Republican, Sen. [WORD ILLEGIBLE] Weicker (Conn.), said yesterday he was going to propose the income limitation be eliminated and total disclosure be the prime [WORD ILLEGIBLE] of the ethics code.

His amendment, Weicker said would require a complete listing of holdings, a net worth statement including all gifts received plus listing publicly of income tax returns.

Weicker, who is heir to a large [WORD ILLEGIBLE] fortune, said in a television interview yesterday that the limitation of earned income without similar [WORD ILLEGIBLE] of investment income would lead to more millionaires in Congress. " [WORD ILLEGIBLE] already are too many," he said.