big issue with consumables w/ plasmacam and a spectrum 2050

[gocanes719]

I use a miller spectrum 2050 with a plasma cam dhc. Today I cut six signs out of a 4x8 sheet. My electrode and tip had a lot of use and started messing up on a portion of the sign I was cutting. Mind you I had cut 5 signs earlier in the last 2 hours. I changed the tip with a 55A tip and the electrode. Tried to continue, the machine cut 10 seconds seemed like it started arcing and quit cutting. I took the tip off and the electrode was welded closed it appear. I tried again with another new tip and electrode two more times and had the same result. Mind you, I'd been using the machine with everything else the same all day same pressures etc. with no issues. I don't think this is a moisture problem and I'm lost as to what this can be. Could I have cut too much too fast? Similar to a duty cycle?