PlasmaCAM torch cable issue

[chuckmerja]

I bought a new PlasmaCAM and techsupport is closed. I really want to get up and running, but am having problems with torch control cable. The trigger control cables seem to be OK, but there's a RED wire and a BLACK wire that hook to torch power and torch ground respectively. The RED wire is OPEN CIRCUIT (infinite resistance). When I got to tracing the wire, I found two components - one in series with RED wire and one jumpers from RED to BLACK.

I believe these are these resistors. They are about the size of 1/4 watt resistors. This is a brand new cable, but both of these components are open circuit (infinite resistance). Even if they are inductors, they should have some low ohmage, right? Like between 1 and 10...

One on right in PIX is blue,gray,yellow, gold should be 680K but is open circuit. And left one is org,org,org,gold should be 33K, but I think it is open circuit too.

thanks,
Chuck Merja
4067995955
chuckm at 3rivers.net

[MQUICK]

What is the problem? What is not working or not happening? Did you zip tie the triger on the gun? You sound like your going through the same steps I did at one time, only to find out the triger on the gun was not tightly zip tied.

[jimcolt]

Those are the voltage divider resistors. They are in the cable to divide the raw arc voltage by 21.1 : 1 in order to supply the correct voltage to the Torch Height Control as well as the arc sensing electronics in the PlasmaCam box. You can either wait until PlasmaCam is open and get a new cable....or you will need to be 100% sure those resistors are open (as you say) and replace them with the correct value. Gnerally if both resistors were open you would see burn marks on them, and to have them fail open you would have to have a direct short on the PlasmaCam (DIN 6 pin plug) end of the cable.

If you are just measuring from one end of the cable to the other for resistance....it will read essentially open. To measure these resistors (now that you have cut apart the cable) you would need to put an ohm meter right across the axial leads of each resistor individually.

Do not attempt to run the PlasmaCam without these resistors.....you will damage the control box. What plasma are your running? You can contact me directly if you want and I'll help you through this. I have a couple of those cables laying around that I could take measurements off. jim.colt@hypertherm.com

Jim Colt