PROBLEM WITH NLS_SORT AND NLS_COMP

 Hello,
I have a problem with the parameters NLS_SORT and NLS_COMP.

When I started the session these are my parameters:

select PARAMETER, VALUE
FROM NLS_SESSION_PARAMETERS
WHERE PARAMETER IN ('NLS_LANGUAGE', 'NLS_COMP', 'NLS_SORT', 'NLS_TERRITORY')

PARAMETER,VALUE
-------------------- --------------------
NLS_LANGUAGE, SPANISH
NLS_TERRITORY, SPAIN
NLS_SORT, SPANISH
NLS_COMP, BINARY

With these parameters, I ran the following query and it works:

SELECT      pieza_serie.pnr,  
            pieza_serie.c_otan_fab,  
            pieza_serie.sn,  
            pieza_serie.iec,  
            pieza_serie.var_edc,  
            pieza_serie.c_pos_edc,  
            pieza_serie.f_ult_ubic,
            pieza_serie.f_cum_vida,