Tweco 400 Ultra-Cut(March 2013) - Manual (Page 89)

Manual No. 0-5163 4-13 OPERATION
ULTRA-CUT 400
You can change consumables by removing power or using the “Plasma Disable” SW.
If you remove power the system does not remember what gasses were last used so it will do a complete purge
including nitrogen buffer even if you do not change gas types.
With “Plasma Disable” the system remembers what was used last and does only the amount of purge neces-
sary possibly saving time.
11. Use “Plasma Disable”.
a) You may use the Plasma Disable when removing the torch cartridge to change or inspect consumables.
Plasma disable stops coolant pump, shuts off all gas solenoids, removes power from the inverter (power
supply) and pilot circuits, inhibits the arc starter ignition (HF) circuit. It does not remove power from
the TSC 3000 or the systems logic and communications circuits so you do not need to go through as long
a power up process after replacing the consumables.
b) If changing to a process with a different gas type you may want to select it before enabling the plasma
otherwise it will start purging the old process and when you do select the new one it will purge again
taking more time.
c) If you are not changing gas type you may want to turn on the Enable first to start the purge while you
enter the process.
12. Shutting off power.
a) If you chose to shut off power for inspecting or changing consumables, or any other purpose, the system
does not remember what you were doing last so you will have to go through the complete sequence from
the beginning starting with step 1.
4.10 Gas Selection
A. Plasma Gases
1. Air Plasma
• Most often used on ferrous or carbon base materials for good quality at faster cutting speeds.
• Air plasma is normally used with air shield.
• Only clean, dry air is recommended for use as plasma gas. Any oil or moisture in the air supply will substan-
tially reduce torch parts life.
• Provides satisfactory results on nonferrous materials and reduced weldability on ferrous materials.
2. Argon/Hydrogen (H35) Plasma
• Recommended for use on 3/4 in (19 mm) and thicker stainless steel. Recommended for 1/2 inch (12 mm)
and thicker nonferrous materials. Ar/H2 is not normally used for thinner nonferrous materials because less
expensive gases can achieve similar cut quality.
• Poor cut quality on ferrous materials.
• Provides faster cutting speeds and high cut quality on thicker materials to offset the higher cost.
• A 65% argon / 35% hydrogen mixture should be used.
3. Oxygen (O
2
) Plasma
• Oxygen is recommended for cutting ferrous materials.
• Provides faster cutting speeds.
• Provides very smooth finishes and minimizes nitride build-up on cut surface (nitride build-up can cause dif-
ficulties in producing high quality welds if not removed).