Check the connection from the voltage pickup to the Qualimaker board.
- Put an isolation between the roll and the voltage pickup.
- The lower voltage pickup should be isolated to the Z-bar.
- Measure from the lower voltage pickup (1) to the upper contact (2) (Z-bar connection). This should be 0 Ohm! (see first picture beside)
- Measure from the lower voltage pickup to the Qualimaker clamp 125/126, one off them should be 0 Ohm! (see second picture beside)
- Measure from the upper voltage pickup to the Qualimaker clamp 125/126, one off them should be 0 Ohm!
- Measure the voltage on Qualimaker clamp 125 to 126 during welding
- the voltage should be between 0.5 and 2.5 VAC