OPERATION
4-10
CommandTHC for X-Y Table
Instruction Manual
5
HD3070, MAX200, HT2000 and HT2000LHF only. Sets ohmic contact
sensing to ON or OFF. When sensing is ON, the torch will advance to the
workpiece during IHS. The nozzle completes an electrical circuit when it
contacts the plate, providing ohmic sensing by the THC.
This parameter should remain ON for most applications. May be disabled
(OFF) to get a more reliable IHS when cutting underwater or when cutting
extremely dirty or rusty metal. Limited-stall-force sensing is always active and
provides secondary sensing to the nozzle ohmic contact sensing.
Nozzle Contact Active
Sets Preflow During IHS to ON or OFF. When this parameter is ON, the
“Plasma Start” and “Hold Ignition” signals will be activated at the start of an
IHS cycle.
The “Hold Ignition” signal makes it possible to increase the overall machine
throughput. This is done by allowing the two normally sequential processes of
IHS and preflow to occur simultaneously. When the IHS cycle is complete
and the torch is positioned at the piercing height, the “Hold Ignition” signal is
deactivated, allowing the power supply to ignite the torch.
Note that the gas preflow time is determined by the plasma system and will
not be reduced by activating this parameter. This function occurs with no
interaction with the CNC and is totally under THC control. Some Hypertherm
power supplies may not include a “Hold Ignition” signal.
Preflow During IHS
Sets a delay to allow the cutting machine to reach a steady cutting speed
before activating the automatic voltage control (AVC). If AVC is active before
the cutting machine reaches a steady cutting speed, the torch may dive
toward the plate. During the Machine Accel Delay time, the torch will maintain
the Set Cut Height.
This delay is based on the cutting machine acceleration time to reach steady
state speed. Set this delay as low as possible without allowing the
torch to dive excessively at the beginning of the cut.
Machine Accel Delay
Sets Auto Kerf Detect to ON or OFF. Reduces the probability of the torch
diving toward the plate when the arc is crossing a kerf. When this parameter
is ON, the THC will constantly monitor the arc voltage for sudden changes. If
a sudden change is detected, the THC will assume the torch is crossing a
kerf and will maintain the torch height until the arc voltage becomes steady,
when AVC is resumed.
If the part being cut does not require crossing a kerf, this parameter should
be set to OFF (inactive).
Auto Kerf Detect
