Thermal Dynamics AUTO-CUT 300 XT, Operating Manual

Page: 57 / 162

AUTO-CUT 300 XT
Manual 0-5300 OPERATION 4-5
Operational Suggestions
1. Wait four minutes before setting the ON/OFF switch to OFF after operation. This allows the cooling fans to run
to dissipate operating heat from the power supply.
2. For maximum parts life, do not operate the pilot arc any longer than necessary.
3. Use care in handling torch leads and protect them from damage.
4. When using water as the shield note the following:
• Use clean drinking quality tap water to help prevent particulate build-up within the system water shield
plumbing.
• Particulate contamination and build-up can cause reduced consumable parts life and premature torch failure.
• A cartridge type particulate water filter may help achieve optimum cutting performance.
4.04 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
substantially reduce torch parts life.
• Provides satisfactory results on nonferrous 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 (O2) Plasma
• Oxygen is recommended for cutting ferrous materials.
• Provides faster cutting speeds.
• Provides very smooth finishes and minimizes nitride buildup on cut surface (nitride buildup can cause
difficulties in producing high quality welds if not removed).
4. Nitrogen (N2) Plasma
• Provides better cut quality on nonferrous materials such as stainless steel and aluminum.
• Can be used in place of air plasma with air shield.
• A good clean welding grade nitrogen should be used.
B. Shield Gases
1. Compressed Air Shield
• Air shield is normally used when operating with air or oxygen plasma.
• Improves cut quality on some ferrous materials.
• Inexpensive - reduces operating costs.
2. Nitrogen (N2) Shield
• Nitrogen shield is used with nitrogen (N2) or Ar/H2 (H35) plasma.
• Provides smooth finishes on nonferrous materials.
• May reduce smoke when used with Ar/H2 plasma.