Arc OK intermitent issues on torch fire

luftlupus wrote: i was told by PCW to wire it that way on the spinena and someothers do it on different pins also.
ill also check into those settings cheers

Ok, so looking at the MESA manual for the 7i76, it looks to me like he told you to do that because the SPINENAs are spindle isolated outputs for controlling spindle direction... but they are special because they are opto isolated outputs coupled with darlington transistors, capable of switching a 50mA load of 0 to 100VDC.

I definitely had a problem with my plasma cutter doing almost the exact same thing I saw in your first video when I had it wired with a Solid State switching device.

I HAD to go to a mechanical, dry contact relay for the torch-on output for it to work. I would be willing to bet you're having the same problem. My guess is that it wasn't near enough current to bias the transistor, and therefore never completely closed the circuit to get a solid start. My pilot arc would be puny sometimes, and sometimes there would be none, sometimes it worked fine. I would get arc-ok lost errors, basically everything you've described.

Switch to a dry contact relay, and use a regular output. I would posit that the problem goes away.

snowgoer540 wrote:

luftlupus wrote: i was told by PCW to wire it that way on the spinena and someothers do it on different pins also.
ill also check into those settings cheers

Ok, so looking at the MESA manual for the 7i76, it looks to me like he told you to do that because the SPINENAs are spindle isolated outputs for controlling spindle direction... but they are special because they are opto isolated outputs coupled with darlington transistors, capable of switching a 50mA load of 0 to 100VDC.

I definitely had a problem with my plasma cutter doing almost the exact same thing I saw in your first video when I had it wired with a Solid State switching device.

I HAD to go to a mechanical, dry contact relay for the torch-on output for it to work. I would be willing to bet you're having the same problem. My guess is that it wasn't near enough current to bias the transistor, and therefore never completely closed the circuit to get a solid start. My pilot arc would be puny sometimes, and sometimes there would be none, sometimes it worked fine. I would get arc-ok lost errors, basically everything you've described.

Switch to a dry contact relay, and use a regular output. I would posit that the problem goes away.

Sorry you mean the internal plasma cutter relay? otherwise i am not using any relays

Also got word back that its a dry contact.

Using the spindle relay is OK on a 7i76. Thats how PCW suggested and it saves an output but I must confess, I never rewired mine from the output I started with after I read his advice.

rodw wrote: Using the spindle relay is OK on a 7i76. Thats how PCW suggested and it saves an output but I must confess, I never rewired mine from the output I started with after I read his advice.

Do you think its worth trying a different output for said connection if that could be the issue? otherwise i am still just racking my brain trying to figure this one out.

luftlupus wrote: Also got word back that its a dry contact.

Your arc ok is a dry contact relay inside the plasma cutter, yes.

I’m saying some machines are sensitive to using a solid state switch to control “torch on”.

This would not work for me, I had to change the torch on to a dry contact mechanical relay. In my case, it’s specifically what Hypertherm calls for. When I get to work I’ll link a video (if I still have one) of what my torch used to do. It’s exactly like your first video.