Tweco SC-3000 - Manual (Page 50)

SC-3000
OPERATION 4-10 Manual 0-5100
Enable Ignition Plasma
• Originally intended to start the plasma, now used to start preflow while finding height when that
feature is enabled (Operator Terminal Preflow set to non-zero)
Separate Ignition Plasma
• Signal activates Start relay on PCB to supply isolated Start to plasma.
OK to Move-PS (plasma)
• Signal from plasma indicating arc transfer has occurred. Is routed directly to the THC and indi-
rectly to CNC controller via OK to Move relay on PCB .
THC Pierce Delay
• Time (parameter set on the operator terminal) following arc transfer that torch remains at pierce or
elevated height.
OK to Move (THC)
• Signal from THC, active at end of THC pierce delay.
CNC Pierce Delay
• Dwell time after CNC receives OK to Move from THC or Plasma before CNC starts torch horizon-
tal motion.
THC Preflow time
• Setting on Operator Terminal (OT) used for preflow during height finding. When the Operator Ter-
minal Preflow is set to zero plasma preflow will not start until THC has positioned torch at pierce
height. Then gas flows for the full plasma preflow time, default setting is 2 sec.
• Setting Preflow to anything other than zero will activate Enable Ignition Plasma sending signal
to the plasma supply’s Preflow On input (when cable is wired to TB2-3&4 of CCM) to start gas
flow at the same time that Initial Position Start is received from CNC. Gas flow starts immediately
and continues until Separate Ignition Plasma sends Start to plasma. If the time has already exceed
the plasma preflow time (default is 2 sec) then pilot ignites immediately. If time has been less than
plasma preflow time, plasma waits for the time remaining before igniting pilot.
THC Control delay
• Often called AVC delay, this is time starting when torch is moved to cut height until THC starts
controlling height to the sampled arc voltage.