Dell OptiPlex DHS Serie Guía De Instalación Y De Referencia Rápida página 18

Verify that the voltage selection switch is set correctly for your location. For
more information, see "When Using Your Computer System" found later in
this document.
4
NOTE: Auto-select power supplies do not require a voltage selection
switch. Your power supply may not have this switch.
Setup and Quick Re ference Guide
17