Plasma torch On OFF automatic solution and voltage

Hi Everybody! I have build up CNC plasma , its done , but now is one problem . I have R-Tech I-Cut100 plasma , HF with pilot arc 100A max. Now I need switch torch ON/OFF automatically. No problem in software level , but problem hop wire/connect torch trigger wires with controller board. What the best way ? I tray connect to my controller board DC/DC relay DC-3-35V /DC 5-110V in 5-110V connect that wire which originally connects with trigger (no relay dead -too much volts I think because HF - maybe I'm not wright). Now is question how get solution for this problem ? Relay? contactor ? solenoid ( not very happy with this solution). Someone know how Volts come in this trigger wire ? (this note same wire who come to plasma electrode) . I very hope to Yours help.

There should not be a high voltage in the trigger (max 24V) unless You connected wrong wires. The trigger is simple button with the cheapest momentary switch inside.