Suddenly no welding, but you can still hear the current! The PM doesn’t show an error and the modulation is okay.

Possible cause:

• With the spring loaded welding pressure system, the upper welding roll should be pushed down by the air pressure cylinder.  When the welding rollers are closed, the cylinder should be released and should not additionally pushing the spring. Because then the welding pressure will be too high.

Corretive:

• Doublecheck the cylinder settings for the lift-up and the drop-down position of the welding roll. Adjust the setting, there might be a loose setting screw!