Hypertherm PAC500 Product Configuration - Manual (Page 23)

1-18 PAC-500
11b THC-1 with Fluidic IHS
As in the THC-2, The THC-1 controls the torch height by arc voltage control. A reference
voltage is set on the THC-1 and when there is a variation in that voltage during cutting,
the torch suspension motor is activated to adjust the torch height. A voltage divider is
part of this system, and is mounted within the power supply. (The voltage divider reduces
the arc voltage from the power supply by a ratio of 25:1. This voltage is then used by the
THC-1 electronic circuitry to adjust the torch height.) Additional features with the THC-1
are:
1. Corner Height Inhibit - This prevents the torch from diving into the workpiece during
corner cutting when travel speed is automatically reduced on CNC machines.
2. Fluidic Initial Height Sensing - This establishes proper piercing height for the start of
each cut. The torch acts as the detection device in this system by generating a high
flow of nitrogen from the torch nozzle. The work piece must be above water for this
system to function properly. (If IHS is desired, but cutting will be under water, see
THC-1 options 11c or 11e).
3. Digital Inputs - The THC-1 accepts digital signals from the machine computer control.
A "Torch On" or "Torch Off" pulse is all that is required from the computer. The
THC-1 provides the control for proper sequencing of the IHS function and
synchronization of torch ignition.
A 30-inch hose and tee are supplied to connect the IHS to the torch side of the control
module.
Note that with this system, cables from the THC-1 module to the IHS, cutting
machine controller, torch lifter and star ground are not supplied by Hypertherm.
Use six-pair 22 gauge cable to connect the THC-1 module to the IHS, and the cutting
machine. Use five-conductor 18 gauge cable to connect the THC-1 module to the torch
lifter motor. Use 18 gauge stranded copper wire to connect the THC-1 module to star
ground (water table), and voltage divider to star ground.
The cable from the IHS module to the control console is also not supplied. Use six-pair
22 gauge cable to connect the IHS module to the control console.
• Locate an area to mount the THC-1 (this should be in easy reach of the operator).
The IHS module should be located as near to the control console as possible. The hose
from the IHS module to the control console is 2-1/2 feet (.76 m) long . Order the system.