Powermax 45xp lost arc delay (Solved)

rodw wrote:

snowgoer540 wrote: Also, here is a video I made when I was having the issue:

Something funny there in that video as there is preflow but no arc. Makes me think its another issue.

Have you got a 7i76e? I thought you were using a 7i96?

Not preflow, what you are hearing is a failed pilot arc, and then the post flow. iPhone didn't really capture the really tiny spark/sputter of a failed pilot arc.

I know it's going to be tough, but you're just going to have to trust me, it was the MOSFET type SSR that caused the problem. It's 100% fixed and reliable now.

The table is wired with a 6i25 and 7i76 combo. I have a 7i96 in the wrapper because at some point I'd like to build another bigger table, and then sell this one (seriously just build the ~5' x ~10' to start if you're questioning it). I would probably rewire this table with the 7i96 and keep the 7i76 if I do. Seems it would make sense as I also have a 7i92 that I used to interface a pi4 to the 7i76 for some "just for fun" playing.

rodw wrote:

snowgoer540 wrote: Also, here is a video I made when I was having the issue:

Something funny there in that video as there is preflow but no arc. Makes me think its another issue.

Have you got a 7i76e? I thought you were using a 7i96?

Maybe you are getting who is who confused. I'm the OP and I indeed have the 7i96. Although the problem seems very very similar.

[strike]So if like to understand the "fix" better. I'm no electrical engineer. Is the fix to put a mosfet on the output ssr pin?[/strike]

Edit: Nevermind. I reread and realized the "fix" in this post is the mechanical relay.
I haven't had a chance to get out to the table and try some of these suggestions out. Freezing the last couple days here.

Nick7251 wrote: Maybe you are getting who is who confused. I'm the OP and I indeed have the 7i96..

Nah, I was referring to snowgoer. I thought he was using a 7i96 but on another thread I saw he had a 5i25/7i76 combo. If I got that wrong I am really confused

I decided to try using my Mesa 7i76e spindle relay while we are exploring this thread but I will post on another thread about that as I had some errors...

The hard thing is that I could get it to work by moving the ground clamp closer to the cutting location for a while then the problem would pop back up. So I'd turn off the cutter and back on and that would sometimes allow it to cut again and sometimes not. Then I'd hit the pulse button and that seemed to get it to cut sometimes and sometimes not.

So I suspect none of those things actually effected anything and it was just intermittent and tricking me. Also the fact it is intermittent makes it hard to duplicate for serious testing and fixing.

rodw wrote: I decided to try using my Mesa 7i76e spindle relay while we are exploring this thread but I will post on another thread about that as I had some errors...

Actually I resolved my error and its possibly relevant so I will post here.
I changed my torch on relay to be the 7i76e spindle enable relay. Removed the plasma cutter wires from my relay and connected to TB4-5 and tb4-6. Once I powered up the 7i76e, the torch came on unexpectedly so I switched off the plasma cutter. Then started up in a more orderly fashion and got a startup error from the plasma cutter which is described in the manual



Active Low seemed interesting and I was aware these digital relays are polarised so I swapped the wires around on the 7i76e and it is working perfect.

So I wonder if problems some people have been having using digital relays is becasue they have the wrong polarity?

I'm going to leave it this way and see how it goes...

Nick7251 wrote: The hard thing is that I could get it to work by moving the ground clamp closer to the cutting location for a while then the problem would pop back up. So I'd turn off the cutter and back on and that would sometimes allow it to cut again and sometimes not. Then I'd hit the pulse button and that seemed to get it to cut sometimes and sometimes not.

So I suspect none of those things actually effected anything and it was just intermittent and tricking me. Also the fact it is intermittent makes it hard to duplicate for serious testing and fixing.

Seems a lot similar to:
"It may be of importance to note: When this was all going on, with the SSR, I noticed that if i had the ground clamp near the torch I had a MUCH higher chance (but not always and the length of time the pilot arc was stable varied) of getting a reliable pilot arc. If I took the ground clamp off the table, it would never fire."
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