Plasma cutting torch-chopper board miss communication

[sam_sam_sam]

We have a plasma cutting machine that cut metal on a table bed

We live in Florida and weather had been raining with 91 to 95 % humility

Here is where the problem starts we had this problem for about 2 years off and on when the weather would be raining and humidity at 90 to 95 % sometimes the plasma would fire and run but not always it would fire but not cut the problem would not stay there to figure out what the problem was

But when you would look at the trouble shooting screen on the machine controller it would not show any error message but the set point for the amperage that CAD program would say 200 amps the set point should be for the chopper should 100 amps for two choppers to = 200 amp but instead of showing the right set point it would show either 0 , 40 , 140 for each chopper which completely wrong

Now last week Tuesday it was raining again with 90 to 95 % humidity and of course here we go again the plasma torch would fire but would not cut and was showing the wrong chopper set points

So I called tech support and they logged in to our machine and technician that was helping with this problem

try a few things which did not work which has been done in the past and this would make the plasma torch work again for a little while and then would do the same thing again

So the tech that worked with me on this problem a few times before says I do not know what going on here

So he had pull the communication cable from the machine controller to plasma controller and clean both ends of the connectors and reinstall them this did not help either

This problem was going on it's second day being on the phone with tech support and not getting any where

Now in the past when we have had problems with CON communication cards on the plasma controller before not communicating with each other but when that happens you get a communication error

and that error would tell which card is having the problem-----****---- not always

So I took the covers where these or cards are and look to see if the cards are communicating with each other they have two LED lights that blink if they are working

I saw some of the card with a light amount of dust on them so I blew them off but that did not help

The plasma torch still would not work so look a the status lights on the chopper boards there are two lights on each board there are four of them they are all ON the ones that should be ON

There is some light dust on these board as well so I blew all four chopper board off as well

Would you know it the plasma torch fire up and now it is cutting and the trouble shooting screen is now reporting the right settings

Now who would of thought that a little bit of dust and very high humidity would cause all this trouble

So I emailed tech support person that was helping me again and told him what I had found and what I had done and his reply was the photo below with Gremlins ?? Above the photo

Which my reply was is there any cure for this

His reply

Bright Lights

My reply was real funny

[ChaosLegionnaire]

Re: Plasma cutting torch-chopper board miss communication

momaka warned me about this before. he said moist dust tends to stick and adhere to surfaces. this can form an insulating layer that can cause heatsinks to perform slightly worse than expected due to dust getting in the way of the heat being dissipated from the heatsink to the air. i guess the same applies to electrical conductivity as well not just thermal conductivity.

i live in a humid tropical climate as well and often experience problems with pci-e, pci, agp expansion cards and dimms not being detected by the mobo. i have to clean the goldfingers on the cards as well as the mobo slot to get the stuff detected by the mobo again.

[kc8adu]

Re: Plasma cutting torch-chopper board miss communication

the dust generated by a cnc plasma is conductive.
thats why i got a samson 5x10 nearly free.
had to clean EVERYTHING!

[Per Hansson]

Re: Plasma cutting torch-chopper board miss communication

^^Exactly.
The dust contains metal particles.
Same problems occur with laser cutting machines.
Same dust created: just much less compared to a plasma since the kerf is not as wide...
I've got a free APC UPS for the same reason

[sam_sam_sam]

Re: Plasma cutting torch-chopper board miss communication

Update

The plasma is cutting at 200 amps so the miscommunication problem is still there I give you an update when I figure out what this problem is the plasma will not cut 400 amps