Hey Guys,

Maybe another set of eyes on this issue couldnt hurt me here.

So I've been in contact with Marcus at geckodrive. Hes great help! Seriously. That guys is in too many places at once. Phone. Email. CNCZone lol. But, maybe some one else's views on this couldn't hurt. I'm scratching my head here.

Here's my panel layout. I left out the 5v control for now because I cant get past powerup without hellfire coming out of it!


Machine has been running great since October. Now I'm in Ohio and we've had some temp swings which caused some condensation in the shop. I waited days til after everything dried up to fire up the machine. She came up fine. Sat idle about 10 minutes. I plugged my USB drive into the pc and stepped back and BOOM! Sparks rained out of the control panel. Ok. Thats not good! My X and Y drives both had green OK lights (G201x's) the Z axis (G203v) said Fault.

I took all her guts inside. Tore through everything. Couldnt find where anything sparked. I mean these were big. ok. Test the faulted Z on a meter. Passes the Gecko test. Take faulted drive to work. hook it up on a 24vdc supply and all green.

Ok....Reassemble panel. Power up 120 -Check
Power up 74VDC - Check
Add drives (without motors) and powerup - sparks!

Dangit!

Only now i found where it came from this time. One of the screws on the back of the Y axis gecko arc'd to the heatsink. Uh. Why? Upon more inspection, it looks like my X axis arc'd to it either previously or just recently. The corner of the case of the drive is all charred.

Amazingly? I remove the drives from the heatsink and power them up one at a time on a different supply- no sparks. No faults. Now I was testing on a 24V switching supply at work.

I put it back in my system. Sparks.

Now, WHY did it start this after all these months? Could it have been the condensation? Possibly. But why wont it stop now?
Marcus over at gecko told me i should have my DC- tied to my AC earth ground. Ok. I dont doubt this. But why wont it stop going ballistic now? Yet one at a time I'm ok.

Leads me to bellieve:
-Ground loop?
-74v is too close to geckos limit? (its 80v and i was assured by Gecko I'm more than ok at 74v)
-Somethings wrong with my linear supply?
-These things really dont like the cold? My G540 Ive run in 0F temperatures just fine. Ive run this system around that temp before i got heat going.
-My mounting screws causing a gap between drive and heatsink?

What am i overlooking here guys?

Thanks a ton!