Types of grounding

When you set up an XPR® cutting system, make sure that you comply with the four types of grounding: service ground, Protective Earth (PE) ground, Direct Current (DC) power ground, and Electromagnetic Interference (EMI) grounding and shielding.

Service ground

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 cutting system and other systems, such as the Computer Numerical Control (CNC) and the motor drives, and the supplemental ground rod connected to the cutting table. In the plasma circuits, the ground is carried from the plasma power supply chassis to the chassis of each separate console through the interconnecting cables.

PE ground

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 Alternating Current (AC) service.

DC power ground

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 cutting system. It requires that the positive cable from the plasma cutting system be firmly connected to the cutting table ground bus with a correctly 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

EMI grounding and shielding is the grounding system that limits the amount of EMI emitted by the plasma cutting system and motor drive system. 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.