There is a section in your operators manual that describes how to inspect the nozzle and electrode for wear.
For most applications...the nozzle wears faster than the electrode due to piercing and blowback damaging the shape of the nozzle orifice. I generally use about 3 nozzles for every electrode.
The electrode wear is indicated by the depth of the pit in the end....when the pit is over a certain depth (listed in your manual....I don't have the manual in front of me at the moment) it will start to misfire. Often you can clean the end with scotchbrite and get some more starts out of it...but not a lot. If you feel the electrode is not lasting as long as it should....then you should look at your air supply.
-moisture or oil or any particulates will cause the electrode pit to wear more rapidly
- setting the pressure LED on the font panel of the Powermax45 higher than recommended will wear the electrode pit more rapidly.
-Lots of pierces wears the nozzle more rapidly....very long duration cuts wears the electrode more rapidly
-using aftermarket or knockoff copies of electrodes (usually indicated by low prices.....some actually have Hypertherm part numbers and name laser marked just as the genuine parts do) will result in lower life and possible overheating damage to the torch body....beware!
Hope this helps,