Contact terminology upright=1.4|thumb|Triple-pole single-throw (TPST or 3PST) knife switch used to short the windings of a three‑phase wind turbine for braking purposes. Here the switch is shown in the open position.
contact terminOlogY uPRight=1.4|thUmB|tRIPLe-Pole single-tHroW (tpST or 3Pst) kNifE sWitcH USEd tO ShORt ThE winDingS OF A thREE‑PhAse Wind TurbIne FoR BrakIng puRposeS. here the SwiTCh IS sHown iN tHe oPen poSItiOn.