Tweco 6000GST Cutting Systems User Manual
Page 18
INTRODUCTION
2-4
Manual 0-2690
D. High Frequency
Because direct current (DC) alone is not sufficient to
strike the pilot arc, high frequency is also used. The
high frequency jumps between the tip and electrode
with the DC following, then the high frequency turns
off.
E. Main Cutting Arc
DC power is also used for the main cutting arc. The
negative output is connected to the torch electrode
through the torch lead. The positive output is con-
nected to the workpiece via the work cable and to
the torch through a pilot wire in the positive lead.
F. Interlocks
Two pressure switches act as an interlock for the gas
supply. If supply pressure falls below minimum re-
quirements the pressure switches will open, shutting
off the power to the contactors, and the GAS indica-
tor, if supplied, will go out. When adequate gas sup-
ply pressure is available the pressure switches close,
allowing power to be resumed for cutting.
A flow switch acts as an interlock for the closed loop
coolant supply. If the flow switch does not activate
then the Power Supply will not power ON. The flow
switch will not activate if there is low coolant level,
or torch front end parts (tip or electrode) are not in-
stalled.