Hypertherm PHC Sensor - Manual (Page 9)

Section 1: Overview 9
Section 1: Overview
Hypertherm’s Sensor™ PHC (228214) is a plasma torch height control/initial height sensing (THC/IHS) system
designed for conventional plasma cutting applications on an X-Y cutting table. The system uses the plasma
arc voltage to control the physical stand-off (distance) between the torch and work piece during plasma arc
cutting. Initial Height Sense (IHS) is accomplished by ohmic contact sensing or by a limited force stall
detection method. The Sensor™ PHC has been optimized for conventional plasma at or below 200 amps.
Note: Sensor™ PHC is not recommended for HyDefinition
®
or HyPerformance™ cutting or for higher power
applications. The system is not recommended for use on a water table.
A complete Sensor™ PHC system includes the following components:
PHC Control Module
The PHC control module (228116) houses a microcontroller, an operator control panel, and a Lifter motor drive.
This unit provides initial height sensing, arc voltage control. The PHC control module interfaces with the torch
lifter, the CNC machine, and the plasma power supply through standard discrete I/O interfaces. The operator
interface includes an LED display for set and actual arc voltage as well as error codes. The control unit main
functions are: arc voltage control/manual position mode, end of cut retract, IHS test, pierce height, voltage
controlled cut height, pierce delay; and access to setup and calibration adjustments. See Figure 2 on page 15.
Plasma Interface Assembly
The plasma interface (228256) provides a clean, standardized connection between the PHC control module
and the plasma power supply. The assembly can be mounted either to the back of or inside the plasma power
supply. The voltage divider provides a filtered low voltage signal which is derived from the cutting arc voltage.
The interface also provides an enclosed terminal block for easy connection to the interface signals. See Figure
3 on page 16.
Lifter Assembly
The torch lifter station (228117) positions a torch head vertically above the work piece and is controlled by the
PHC control module. Its maximum standard stroke is 6 inches (152 mm) between home and the lower limit. It
is driven by a DC motor attached to a lead screw. The control module interfaces with an optional lower limit
switch to detect maximum travel downward. The control also interfaces with an optional home switch to detect
when the lifter is in the highest position. The standard lifter does not use limit switches but has been designed
to allow for hard stop limit detection. A power-off brake disables power off motion of the torch. A torch
breakaway is an integral part of the lifter and provides a level of protection for the torch, lifter and X-Y table.
Upon impact, the breakaway releases from the locked position and allows the torch to float. A breakaway
switch detects when this protection has tripped and signals both the PHC control and the CNC machine. See
Figure 4 on page 17.
Sensor PHC Models
Kit Number Description
228214 Sensor PHC with control module, lifter, and 50-foot cables
228123 Sensor PHC (with 123896) for Powermax bundle
228242 Sensor PHC without lifter station
228243 Sensor PHC without lifter or 123895
228244 Sensor PHC without control module
228245 Sensor HPC without plasma interface