Hypertherm HPR260 Manual Gas Preventive Maintenance Program Rev.5 - Manual (Page 57)

INSTALLATION
3-8 HPR260 Auto Gas Instruction Manual
5
12. If the gantry runs on rails that are not welded to the table, then the rails need to be connected with a ground cable
from each end of both rails to the table. These need not go to the common (star) point, but could take the shortest
path to the table.
13. If the OEM is installing a voltage divider to process arc voltage for use in the control system, the voltage divider
board should be mounted as close as possible to the point where the arc voltage is sampled. One acceptable
location is inside the plasma power supply. If the Hypertherm voltage divider board is used, the output signal is
isolated from all other circuits. The processed signal should be run in twisted, shielded cable (Belden type 1800F
or equivalent). The cable used must have a braided shield, not a foil shield. The shield should be connected to the
chassis of the power supply and left unconnected at the other end.
14. All other signals (analog, digital, serial, encoder) should run in twisted pairs inside a shielded cable. Connectors on
these cables should have a metal housing and the shield, not the drain, should be connected to the metal housing
of the connectors at each end of the cable. Never run the shield or the drain through the connector on any of the
pins.
Example of a good cutting table ground bus. The picture above shows the connection from the
gantry ground bus, the connection from the ground rod, the power supply positive lead, the RHF
console*, the CNC enclosure, the torch holder, and the power supply chassis.
* Applies to systems that use a remote high frequency (RHF) console
Gantry
Ground rod
Power
supply
lead (+)
Remote
high frequency
(RHF) console
CNC enclosure
Torch holder
Power supply
chassis