Ohmic Probe Triggers Early or Between Cuts

Background

Ohmic probing relies on a calibrated resistance value between the torch cap and your workpiece.

Make Sure the Torch Cap is Dry

Reason: Plasma Torch Cap is wet.

Water in the torch cap can cause ohmic probing to trigger because it creates a circuit between the torch nozzle (Arc-) and cap. Since the nozzle is electrically connected to the workpiece clamp (Arc+) by the arc voltage divider, this can trigger the ohmic probe.

1. Use the TEST TORCH button to purge the torch cap. Make sure to jog away from the workpiece first.

2. Using compressed air, blow any water of your torch cap.

3. Adjust ohmic touch sensitivity as detailed below.

Adjust Ohmic Sensitivity

Reason: Ohmic touch sensitivity adjusted incorrectly.

Ohmic touch sensitivity may need to be adjusted when you switch between styles of consumable or torch cap.

1. Position the torch in above the workpiece in a small puddle of water, so that the torch cap is touching the water but not the workpiece.

2. Open the electrical cabinet and locate the Tormach THCT board (PN 39096)

3. Adjust the “RV1” potentiometer counterclockwise to decrease the sensitivity until the ohmic probe is not triggered by the water but is still triggered if you lift the workpiece to touch the torch cap.