Schaublin 125-CNC retrofit.

Aciera wrote:

Given that there is no energy stored in the inductor (ie no collapsing magnetic field) I don't see where that voltage would come from.
 

Me either, but I don't know everything about magic smoke.  Like maybe there's some sort of induced field in the coil when the main contacts make/break - and I've never learned about this situation but it's obvious to everyone else.

Once the magic smoke discussion moves past my internal understanding of "electricity is like water through a hose, only not" I have to start asking questions.

a 20ohm fuel injector charged with 12v dc, can emit s much as 140v on shutoff depending on operating FZ and duty cycle.

a typical 24vdc contactor coil has a impedance of around 30-50 ohm. The flyback voltage could easily reach 140-200v on coil off especially if the contacts bounce as the field collapses. It's worth a look. ALOT of DC coils have built in diodes to prevent this, but maybe this unit does not. 

@SMC
seems you have not seen his video on youtube, he pushes the relays by hand/screwdriver and still gets the error, so no relays in use.

So this is how far I got so far...


Cheers,
Mark

No doughnuts!

Ahhh, don't you just LOVE software solutions?
Nothing like 'fixing' a difficult hardware problem with your mouse and keyboard.