I didn't say panels are a fire hazard but the moving plastic can build up static electricity and the grounding would help get rid of the built up charge according to the engineer. First let me say that the fact you replied to my reply tells me yours is not the TROLL,chain yanker post I first thought it was.

Jon, most fires are going to go the way the air is blowing be it trash or dust. There was no trash to speak of in the engine compartment but there was a lot of dust stuck to the sides of metal, filters, and such like wet snow sticking to trees when it comes down with the wind blowing. It was only 10 hours old so surfaces were still rough and not shined up so things would stick better. Do you never get zapped when reaching out to touch a hand rail?  No,that is the frustrating thing,I have never experienced the slightest shock from touching a combines ladder rail and the ground,so I always suspected that the electrical charge on a combine was small to none. If a static electricity charge did form on a combine,it can not manifest itself as a hot spot in the center of a dusty side panel. electricity has to jump from one point to another with positive and negative electrical charge. The voltage needed to jump through the air from a combine panel several feet off the ground to the ground would have to be in the million possibly millions of volts range. Ed's experiment showed that static charges of only a few thousand volts  are discharged by carbon black in the tires as effectively as though the combine was connected to a ground rod.   And the static is not sparking from the panel to the air,air is a fantastic insulator,which is why we can run 500,000 + volt power lines through it for hundreds of miles without losing a large amount of power from the lines.

Did the 2388 you look at not have any plastic on any fan or no plastic cones on the shafts above the straw spreaders? I'm no 2388 expert and didn't look at the one very long after the fire. I heard the report from the dealer a couple days after the fire so I haven't looked at it since they brought up the static electricity theory.

I read Ed's post about static electricity and his comment that "some also believe that static discharge sparks could be a cause of fires on the combine" so I told my experience. This is in the Pacific Northwest with high temperatures and low humidity and a lot of dust in the wheat this year. There are engineers working for the manufacturers who are studying the issue even if you give it a full BS.

Sorry let me say again that I now realize that the intent of your post is not as bogus as I originally thought. I just get so frustrated seeing people risking their lives/combines/crops chasing phantom static sparks when the real danger is fires started by the hot exhaust system of the combine. In my area we harvest sunflower which puts out an oily fuzz which burns like finely shredded newspaper soaked in diesel fuel. The eye opener for me was being an observer up at the engine compartment of my combine at night while harvesting sunflower in very low humidity conditions. The area around the hot exhaust manifold and turbo is a cloud of flammable fuzz,and when one of these bits of fuzz get within an inch or so of the hot parts,it lights into a burning ember that will glow for as much as 30 seconds,drifting many feet before burning out. If one of these burning embers lands in a fuel supply,you have a spontaneous fire.  During daylight hours or with artificial light,these burning embers are invisible,so it is easy to not know they are there.

 Another thing that makes me believe the static theory is bogus,is that the pull type, pto powered combines used in my area never have fires while the self propelled machines are lighting up all around them ? The only difference is that there is no engine with hot exhaust system on a pto driven combine,and the tractor exhaust is too far away(30 ft out in front) to see any effect from the combine dust.

I feel very lucky that my field pea was disease free this year,as that flammable mold dust sounds like some very nasty stuff to deal with. I strongly believe that a layer of this stuff burning on a combine panel was lit by a floating ember lit by the exhaust,and not some phantom static spark.

Another frustrating thing about the combine dust fires seems to be that it needs just the right combination of wind and humidity to make them happen,just a slight change makes the difference between fires/no fires. I have had fires one day and no fires the next day after adding a drag chain which led me to believe we had found a fix,but the next day when the"right" weather conditions returned,the fires were back.

The only effective fix I have found is to carry a leaf blower to the field and blow all the dust/trash/fuel off the combine often,sometimes at every tank unload, to give the fires no place to start.