Powermax 45xp lost arc delay (Solved)

PCW wrote:

Note that a normal external SSR block type relay's would not be expected to work well
as these often need a minimum current and have significant voltage drop because they use
bipolar transistors and must get their base drive from the switched power side

A MOSFET type SSR would be superior to a mechanical relay

In the interest of trying to understand why a MOSFET type SSR wouldn't work in my case, attached is the data sheet for the exact MOSFET type SSR that I had issues with. Any insight into why it didn't work reliably would be appreciated, as I said, I like to learn new things

Here is a link to the product as well (it was not cheap): www.grainger.com/product/SCHNEIDER-ELECT...D26BD&searchBar=true

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

I thought I had made one of pulsing with mechanical relay... but just picture a torch pulse with pilot arc as it should

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. With a mechanical relay, I could disconnect the ground clamp and it still reliably pilot arc's for the proper length of time. In fact, I discovered the problem was the SSR by simply touching the two wires together while the ground clamp was disconnected (after I confirmed that a manual torch didn't need to be near the ground clamp to fire reliably). It sure was a roller coaster for a few days, but it got sorted

One final test may be to hook the works up to the 7i76's spindle on SSR and see if I had similar results, but as mentioned, after I went to a mechanical relay, it's been 100% reliable, so I never really looked back.

I will still try to get torch on amperage from my powermax 65 when I get a few.

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.

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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