Tweco 20 O2 Auto-Cut - Manuel (Page 74)

Manual No. 0-4816 Auto-Cut 200
2
4-8 OPERATION
Pressure and Flow Setting
1. Set the Preflow (Piloting) gas pressure.
a. Set the Mode switch to “SET PREFLOW”. Refer to the torch section of the manual (cut charts section 8)
for proper settings.
b. Use the Preflow regulator knob to set preflow gas pressure. If the Mode switch is left in the “SET
PREFLOW” position for 2 minutes, the flow will be shut off.
2. Set the Plasma gas pressures and flows.
a. Set the Mode switch to “SET PLASMA & SHIELD”. Refer to the torch section of the manual (cut charts
section 8) for proper settings.
b. Use the Plasma regulator knob and pressure gauge to set plasma pressures. Next, set the flow using the
flow meter and knob above it.
3. Shield gas pressures and flows (except for N
2
/H
2
O process).
a. Set the Mode switch to “SET PLASMA & SHIELD”. Refer to the torch section of the manual (cut charts
section 8) for proper settings.
b. Some cut chart processes will specify both a pressure and a flow setting and other just a pressure
setting. If both are required, set the Shield Gas switch to “Flow”. If only the pressure is specified, set the
Shield Gas switch to “Pressure”.
c. Set the Shield Pressure using the Shield regulator knob and pressure gauge. If required, set the Shield
flow using the Shield Flow meter and knob above it.
4. N
2
/H
2
O process set H
2
O MIST
a. Set the Mode switch to “SET PLASMA & SHIELD”. Refer to the torch section of the manual (cut charts
section 8) for H
2
O Mist settings.
b. Use the H
2
O Mist control knob and flow meter to set water flow rate.
5. Place the MODE switch to the “RUN” position.
6. Cutting Current
a. Adjust current control digital thumbwheel switch for the desired cutting current.
System is ready to cut.
When switching gases between operations, allow enough purge time to clear the prior gas from the torch leads.
If during the set process either preflow or Plasma / Shield stops due to the 2 minute timeout, switching to RUN and
back to the SET position will give another 2 minutes of gas flow.
While nothing prevents the operator from switching gases during piloting or cutting it is not recommended to do
so. If the operator switches gases during piloting or cutting, the arc stops, then the system purges the new gas.
Switching gases during piloting or cutting may damage torch parts or the piece being cut.