Torch will not turn off when hooked to controller

The way to tell is what your consumables look like. They should look like this for blowback start:

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It is a HIGH FREQUENCY plasma cutter…It will NOT work on the Langmuir table…

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George, is the photo shown in

a spark gap that’s used in HF start systems or is it just something else?

Yes they are the HF points. And as far as I know all Lotos plasma cutters other then the 5500 are HF.

our Guru of Plasma cutters @mechanic416 has cleared the air…it is a HF start…

do not use it on the table…that is why we ask for people to clarify what plasma they are using…

So many people are getting into Plasma that sales people will sell you just about anything to get you out the door


Thanks for the help guys! Got new relay in and ordered this plasma cutter should be in monday!

I’m super frustrated torch will not turn off no matter what it’s stuck in on position beep test proves it with new relay heeellllpp please everything works proper

Everything but torch control that is

My guess is you have the torch trigger wired wrong in the plasma cutter.

Torch is in the on position even if not hooked up to plasma cutter

Nothing hooked up controller is in on position

Then most likely the controller is shorted/bad. If its the same one you had when trying to use the HF plasma cutter it may have shorted it out.

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Yes I am thinking that

Sucks I’m 9 weeks waiting and nothing

I had this problem as well and I contacted Langmuir and was sent a new Torch Fire Relay like in the photo above, but it wasn’t the relay that was my problem, it was the Motion Control Board (MCB) that the Relay plugged into. -Apparently, a failed component in the Motion Control Board will cause a failure to block the 36V AC from energizing the Torch On/Off relay coil. -Contact Langmuir and run through their tests and they can can help you… Torch stuck in ‘On’ is likely one of them (either the Relay or the MCB).