FUNCTION ConvertClob(sInp IN CLOB, dest_char_set IN VARCHAR2, source_char_set IN VARCHAR2) RETURN CLOB AS
      sOut              CLOB;
      nPos              PLS_INTEGER := 0;
      nLen              PLS_INTEGER;
      nLength           PLS_INTEGER := LENGTH(sInp);
    BEGIN
     WHILE nLength>nPos LOOP
       nLen := INSTR(sInp, CHR(10), nPos + 4000);
       IF nLen=0 THEN
         nLen := nLength;
       END IF;
       --sOut := sOut || utl_raw.cast_to_varchar2(UTL_RAW.Convert(DBMS_LOB.SUBSTR(sInp,nPos+1,nLen-nPos),'AMERICAN_AMERICA.RU8PC866', 'AMERICAN_AMERICA.AL32UTF8'));
       sOut := sOut||CONVERT(TO_CHAR(SUBSTR(sInp,nPos+1,nLen-nPos)), 'RU8PC866');
       nPos := nLen;
     END LOOP;
     RETURN sOut;
  END;

sOut := sOut || utl_raw.cast_to_varchar2(UTL_RAW.Convert(DBMS_LOB.SUBSTR(sInp,nPos+1,nLen-nPos),'AMERICAN_AMERICA.RU8PC866', 'AMERICAN_AMERICA.AL32UTF8'));

ORA-06502: PL/SQL: : ошибка преобразования из raw в шестнадцатеричное ошибка числа или значения

v_clob_convert := convert('Привет:::Пока', 'RU8PC866');
v_blob := clob_to_blob(v_clob_convert);

function clob_to_blob (p_clob in clob) return blob
    as
     l_blob          blob;
     l_dest_offset   integer := 1;
     l_source_offset integer := 1;
     l_lang_context  integer := DBMS_LOB.DEFAULT_LANG_CTX;
     l_warning       integer := DBMS_LOB.WARN_INCONVERTIBLE_CHAR;
    BEGIN
      DBMS_LOB.CREATETEMPORARY(l_blob, true);
      DBMS_LOB.CONVERTTOBLOB
      (
       dest_lob    =>l_blob,
       src_clob    =>p_clob,
       amount      =>DBMS_LOB.LOBMAXSIZE,
       dest_offset =>l_dest_offset,
       src_offset  =>l_source_offset,
       blob_csid   =>DBMS_LOB.DEFAULT_CSID,
       lang_context=>l_lang_context,
       warning     =>l_warning
      );
      return l_blob;
    END;