Hypertherm HPR260 Manual Gas Preventive Maintenance Program Rev.5 - Manual (Page 56)

INSTALLATION
HPR260 Auto Gas Instruction Manual 3-7
5
Steps to take
1. Unless noted, use only 6 AWG (16 mm 2 ) welding cable (Hypertherm part no. 047040) for the EMI ground cables
shown on the diagram (blue).
2. The cutting table is used for the common, or star, EMI ground point and should have threaded studs welded to the
table with a copper bus bar mounted on them. A separate bus bar should be mounted on the gantry as close to
each drive motor as possible. If there are drive motors at each end of the gantry, run a separate EMI ground cable
from the far drive motor to the gantry bus bar. The gantry bus bar should have a separate, heavy EMI ground cable
(4 AWG part no. 047031) to the table bus bar. The EMI ground cables for the torch lifter and the RHF console
must each run separately to the table ground bus.
3. A ground rod that meets all applicable local and national electrical codes must be installed within 6 m (20 ft) of the
table. This is a PE ground and should be connected to the ground bus on the cutting table with 6 AWG
green/yellow grounding cable (Hypertherm part number 047121) or equivalent. All PE grounds are shown on the
diagram in green.
4. For the most effective shielding, use the Hypertherm CNC interface cables for I/O signals, serial communication
signals, power supply-to-power supply multi-drop connections, and interconnections between all parts of the
Hypertherm system.
5. All hardware used in the ground system must be brass or copper. The only exception is that the studs welded to the
table for mounting the ground bus can be steel. Under no circumstances should aluminum or steel hardware be used.
6. AC power, PE, and service grounds must be connected to all equipment according to local and national codes.
7. * The positive, negative, and pilot arc leads should be bundled together for as long a distance as possible.
The torch lead, work lead, and the pilot arc (nozzle) leads may only be run parallel to other wires or cables if they
are separated by at least 150 mm (6 in). If possible, run power and signal cables in separate cable tracks.
8. * The ignition console should be mounted as close as possible to the torch, and must have a separate ground cable
to the bus bar on the cutting table.
9. Each Hypertherm component, as well as any other CNC or motor-drive cabinet or enclosure, must have a separate
ground cable to the common (star) point on the table. This includes the ignition console, even if it is bolted to the
power supply or to the cutting machine.
10. The metal braided shield on the torch leads must be connected firmly to the ignition console and to the torch. It must
be electrically insulated from any metal and from any contact with the floor or building. The leads can be run in a
plastic cable tray (track) or covered with a plastic or leather sheath.
11. The torch holder and the torch breakaway mechanism – the part mounted to the lifter, not the part mounted on
the torch – must be connected to the stationary part of the lifter with copper braid at least 12.7 mm (1/2 in) wide.
A separate cable must run from the lifter to the bus bar on the gantry. The valve assembly should also have a
separate ground connection to the gantry bus bar.
* Applies to systems that use a remote high frequency (RHF) console