[ny_racer_xxx]

I have a home built unit Plasma table, everything has been working fine I have a Proma THC unit all is well.

The only issue I have are the relays I'm using for the Ohmic Touch off. They burn up quite often. They are cheap low voltage units and I do understand when it's cutting the plasma cutting voltage/current is smoking the relays...

At Least it's not smoking the BOB!!!!

Does anybody have a decent relay they can suggest that they have used in this application?

Thanks!!

CR

[Torchhead]

While using a simple relay as the touch off sensor for ohmic appears to be a good idea you need to prtect the coil and the power supply that is in contact with the sensing side. You can get large voltage spikes and reverse voltages that can cause arcing. no relay that is not wired right will last . The circuit needs high voltage blocking diodes and over voltage protection (current limiting) having the sense side disconnected anytime the torch is fired (takes another relay and still needs some protection) will increase the life of your sensor by a factor of 10 or more.

[ny_racer_xxx]

Understood and I'm using a two relay system similar to one I found here...

I appreciate your expertise, but what I'm looking for is somebody with a working system that can point me to the correct components....

Thanks again...

CR

[ny_racer_xxx]

I found this on feebay

Attachment 329816

Neuron Ohmic Sensor for CNC Plasma Cutting | eBay

I think this will do the trick....

[ny_racer_xxx]

Anyone try one yet???