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My company is an OEM in the packaging industry We currently produce a machine which is P.C. controlled. We have noticed that the P.C. malfunctions due to an ESD event. The static build up occurs in the conveyor system as we drag a nylon conveyor belt across a polycarbonate support screen. There are additional problem areas along the conveyor where rubber rollers pinch the belt to drive it along creating a peeling action. I have used a static measuring device which verifies my concerns. I would like to suppress the electrical disturbance resulting from the ESD before it reaches the p.c. We are using a line filter and surge suppressor already but they don’t seem to help the situation. The ESD disturbance is very brief (around 15 microseconds) but powerfull. Is there any kind of filter or suppression device to control this type of transient. I understand that controlling the source of the ESD is another option but I’d like to explore any possible filtering first! -Anonymous !

You might try a fast response (in nanoseconds if one exists) MOV (metal oxide varistor) that clamps well below the ESDS classification for your most sensitive device and put these across all line inputs (hot to ground, neutral to ground, hot to neutral).

The best solution would be to change the materials so triboelectric generation is not involved. In lieu of this, ionization across the conveyor belt at the hot spots would reduce the chances of ESD events occurring. You can also try topical treatments on the conveyor system and rollers, but the surfaces treated may need repeated treatments as the coating wears off.

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