EDGE Pro Ti CNC Instruction Manual 807660 43
Installation
Mounting the THC
Recommended grounding and shielding
Introduction
This section describes practices for grounding and shielding a plasma cutting system to minimize its susceptibility to
electromagnetic interference (EMI) (also known as noise). It also describes the service ground, protective earth (PE)
ground, and DC power ground. The diagram at the end of this section shows these types of grounds in a plasma cutting
system.
Note: The grounding practices in this section have been used on many installations with excellent results, and
Hypertherm recommends that these practices be a routine part of the installation process. The actual methods
used to implement these practices may vary from system to system, but should remain as consistent as possible.
However, due to the variation in equipment and installations, these grounding practices may not succeed in every
case to eliminate EMI problems. Hypertherm recommends that you consult your local and national electrical codes
to make sure that the grounding and shielding practices that you use satisfy the requirements for your location.
Types of grounding
Service ground (also known as safety ground) is the grounding system that applies to the incoming line voltage. It
prevents a shock hazard to any personnel from any of the equipment or the cutting table. It includes the service ground
coming into the plasma system and other systems, such as the CNC and the motor drives, as well as the supplemental
ground rod connected to the cutting table. In the plasma circuits, the ground is carried from the plasma system chassis to
the chassis of each separate console through the interconnecting cables.
Protective earth (PE) ground is the grounding system inside the electrical equipment. The PE ground, which connects
to the service ground, provides electrical continuity between the equipment and the AC service.
DC power ground (also known as cutting current ground or work) is the grounding system that completes the path of
the cutting current from the torch back to the plasma system. It requires that the positive lead from the plasma system be
firmly connected to the cutting table ground bus with a properly sized cable. It also requires that the slats, on which the
workpiece rests, make firm contact with the table and the workpiece.
EMI grounding and shielding is the grounding system that limits the amount of EMI emitted by the plasma and motor
drive systems. It also limits the amount of EMI that is received by the CNC and other control and measurement circuits.
The grounding practices described in this section mainly target EMI grounding and shielding.
To Next Page
Loading...
Need help?
General
