AB 842E Absolute Ethernet IP encoder + Static discharge.

I ran into some trouble with an 842E Encoder, and what appears to be a problem with static charge building up from a product line and then discharging.

I had an encoder just keep faulting communications, and would require power to be removed and turned back on before it would communicate again.

I checked cable wiring and shielding, rerouted all cables away from any other potential power or signal cables, replaced cables, put the encoder and the ethernet switch on isolated power supplies dedicate to only that purpose, double and triple checked all grounding connections on the machine, even electrically isolated the mount for the encoder, but nothing seemed to help. As soon as the material moving on the conveyor touched the machine base, the encoder faulted.

I put a voltmeter on the product material moving down the conveyor and as soon as it started moving, it built up about 550VDC (reference to Ground). The material is Aluminum and the rollers are made of rubber and soft cloth material.

For testing purposes, I draped a bare copper wire across the material and attached it to ground. After this, there was only about 8VDC built up, and the encoder never faulted.

Now I need to find a soft material that is conductive, so I can have it make contact with the material, but not damage it in any way. Or find out how to make the encoder not fault when the static discharges on the machine near it.

Any tips? Thanks.

I think I found a solution.
http://precisionbrush.com/conductive-strip-brushes-thunderon
http://precisionbrush.com/conductive-strip-brushes-conductive-nylon

And it seems like either of these two options would be soft enough to not damage or mar any surface.

I can't help but think I'm only covering up an issue though. Given the materials, I'm sure there is nothing I can do about static build up. I'm rubbing metal against rubber and cloth. But the encoder being zapped by this discharge just seems odd. But I've tried everything I can think of to try to stop this static from reaching the Encoder, and no luck so far.

What about an Ionizer bar,Gun,? We have these on our process. You will know when they are not working because when you get within about a foot of the material a nice blue arc will jump out and grab you. Hurts like Hades.

As long as the Ion guns are working you can touch it all day long.

Had not really heard of those before. A quick look at them seems promising. I wonder how well one would work with a 200 foot long piece of material rolling down a set of rollers.

It may be an option if the brushes end up damaging the material or not holding up to the material running along it all day long.

I guess it would depend on placement and how long it takes it to build up to a voltage that causes issues.

I don't know if you use any Keyence products but the make some fairly large ion static units and I assume like their sensors they will bring you one to try out for 30 or 45 days before you buy. That may be an option and do some temporary placement until you find the sweet spot.

I think the following two materials can help you have it make contact with the material, but not damage it in any way. And cable strip brushes make the encoder not fault when the static discharges on the machine near it：
https://www.aoqunbrush.com/cable-brushes-strip_c9