Appendix f system grounding, Appendix f, System grounding requirements – Hypertherm HT4001 Plasma Arc Cutting System User Manual
Page 256: Suggested ground cable routing
HT4001
Instruction Manual
f-1
System Grounding Requirements
The plasma system must be grounded for safety reasons and to suppress EMI:
• Safety The entire system – power supply, accessory enclosures, and worktable – must be grounded to
protect it and the operator from a ground fault. The protective earth (PE) ground connections must be
installed by a licensed electrician and conform to national and local codes.
• EMI Suppression If allowed by national and local codes, the ground system can also be used to suppress
EMI (electromagnetic interference). Below is a guide to configure the plasma system for minimal EMI. See
Electromagnetic Compatibility in this manual for additional information.
Suggested Ground Cable Routing
Power Supply
Connect the power supply to the PE ground terminal, using a properly sized color-coded conductor. This PE
ground is connected to the service ground through the line disconnect switch. See the Installation section for
further information on the power cord and the line disconnect switch.
Equipment Grounding
All accessory modules that receive power from the plasma power supply must also use the power supply’s
ground – either by connection to the PE terminal of the power supply, or by direct connection to the
equipment ground conductor. Each module should have only one connection to ground to avoid ground loops.
If any enclosure is grounded to the work table, the work table must be grounded to the power supply.
Effective grounding for EMI reduction is highly dependent upon the installation configuration. Two acceptable
configurations are shown in Figures f-1 and f-2.
The RHF console should be installed near the work table, and grounded directly to it. Other modules should
be installed near the power supply, and grounded directly to it (Figure f-1).
All modules may also be installed near the work table, and grounded directly to it (Figure f-2). Do not ground
the RHF console directly to the power supply.
The customer must furnish all conductors for equipment grounding. Grounding conductors may be purchased
through Hypertherm in any length specified by the customer (Part No. 047058). The conductor may also be
Appendix F
SYSTEM GROUNDING