A start input signal is sent to the power supply.
This simultaneously activates the open circuit voltage
and the gas flow to the torch Open circuit voltage can be measured
from the electrode (-) to the nozzle (+).
Notice that the nozzle is connected to positive in the power supply
through a resistor and a relay (pilot arc relay),
while the metal to be cut (work piece) is connected directly to positive.
Gas flows through the nozzle and exits out the orifice.
There is no arc at this time as there is no current path for the DC voltage.