Hypertherm HT4400 HySpeed Plasma Arc Cutting System - Manual (Page 71)

OPERATION
4-12 HT4400 Instruction Manual
Common Cutting Faults
• Torch pilot arc will initiate, but will not transfer. Causes can be:
1. Work cable connection on the cutting table is not making good contact.
2. Malfunction in the HT4400 system. See Section 5.
• The workpiece is not totally penetrated, and there is excessive sparking on top of the workpiece.
Causes can be:
1. Current is set too low (check Cut Chart information).
2. Cut speed is too high (check Cut Chart information).
3. Torch parts are worn (see Changing Consumable Parts).
4. Metal being cut is too thick.
• Dross forms on the bottom of the cut. Causes can be:
1. Cutting speed is too slow or too fast (check Cut Chart information).
2. Arc current is set too low (check Cut Chart information).
3. Torch parts are worn (see Changing Consumable Parts).
• Cut angle is not square. Causes can be:
1. Wrong direction of machine travel.
High quality side is on the right with respect to the forward motion of the torch.
2. Torch-to-work distance is not correct (check Cut Chart information).
3. Cutting speed is not correct (check Cut Chart information).
4. Arc current is not correct (check Cut Chart information).
5. Damaged consumable parts (see Changing Consumable Parts ).
• Short consumable life. Causes can be:
1. Arc current, arc voltage, travel speed, motion delay, gas flow rates, or initial torch height not set
as specified in the Cut Charts.
2. Attempting to cut highly magnetic metal plate (some metals such as armor plate with a high nickel content)
will shorten consumable life. Long consumable life is difficult to achieve when cutting plate that is
magnetized or becomes magnetized easily.
3. Not beginning or ending the cut on the plate surface. To achieve consumable long life, all cuts must
begin and end on the plate surface.
Also see Cutting Techniques later in this section for methods to improve cutting performance.