Problem with THC 301D

[vishnu]

This is the first time i am starting to cut on 8 mm Mild Steel. I have peculiar problem. My torch pierces and when it starts to cut it goes up from intial cut height of 1.6 mm to 9 mm ,which is the upper limit i have set and then stops and the final arc volts reads 190 upwards. This is the first time i have encountered such a problem.

My Settings for 8 mm Mild Steel are

Arc voltage 139
Pierce rate 25 IPM
cutting speed 75 IPM

Please help.

[larryy1022]

check yr upper limit switch if it has problem, it might keep sending up signal.
and check the dross of torch,

the strange thing is plasma reads 190, torch should dive on voltage spike, if your THC has no auto mode freeze function.

But your torch keeps going up.

larry