Powermax 45xp lost arc delay (Solved)

I'll see if I can get the current flow through the torch fire connections in a couple of hours this evening. on my hyperthem Powermax 45 (non-XP) out of curiosity.

The relays I've used for this sort of an application are these:

COTO 9001 available in 5V or 12V
www.farnell.com/datasheets/1533707.pdf

given I am now running 24V via the 7i76E I have changed to these:
docs.rs-online.com/f767/0900766b8163793d.pdf

I also like these relays (I have a good supply of them) for other uses:
www.fujitsu.com/downloads/MICRO/fcai/relays/ry.pdf
They have a fairly low minimum switching load at 10mA
And are available in a good range of coil voltage ratings
With good switch and release times.

They are all from good (known) manufacturers and the datasheets are comprehensive (in my opinion) unlike buying from far away shores....

well I measured the current through the torch fire pins of the CPC for my hypertherm powermax 45 (nonXP) and got something interesting....

on milliamps scale with a Fluke 88 automotive DVM I got a current starting at about 11mA and rising up to 16mA over a period of about 45 seconds (it rose rapidly and tapered off.... indicating the charging of a capacitor)

I'll give it a go again tomorrow and time it properly from a discharged (unused) state. voltage was measured at 18.5v between open circuit terminals.

oh may be of interest to the minimum current requirements for reed relays
knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000kFOySAM

PCW wrote: A MOSFET type SSR would be superior to a mechanical relay

This is the Mosfet one I now use where ever a DC relay is required.
au.rs-online.com/web/p/solid-state-relays/8886843
Just you have to buy 5 of them. That was not a problem when I first started but smarter circuits devised in this community has reduced the relay count to just one for torch on and by all accounts the 7i76e spindle relay can make it redundant too. I like the LED to show when its active.

I tried to measure the current on my thermal dynamics today but was unable to do so with my multimeter in the circuit. The torch did not turn on.

I think you may need an inductive current meter. Or I have previously blown a fuse.

Most DVM have 2 fuses, one for low current range the other for the 10 or 20A section.
Usually the small one goes out (200mA in most cases), so use the 10 or 20A range to test, not precise for this but you get a rough idea.

I started off on the higher range first (just in case... I didn't want to kill my fluke)

then put it down to the mA range