Air shutoff issues - PP50 & S45 Torch

I’m hoping someone could help me out on this. Maybe a user or Everlast Tech Support.

I have the PowerPlasma 50 with the S45 torch hooked up to a CNC machine. I keep the air pressure set around 75 psi for cutting. The torch fires when it should, it cuts fine and the arc turns off when it should, but the air does not turn off. If the air does not shut off, the torch can not strike the pilot arc for the next cut to begin. In order for the air to turn off, I have to bleed the air from the machine for a split second and the air will turn off. (from a relief valve I have hooked up in the shop air coming to the plasma machine).

Initially I thought I had a weak air solenoid inside the plasma machine. I disconnected the air line between the plasma machine and the torch and tried to replicate the problem by turning on the “constant air” air switch and I could not get the air to stick on. I reconnected the airline to the torch, tried it again and the air stuck on. So from that, I don’t think it’s the solenoid in the plasma machine.

I then moved on to thinking it may be the torch itself that for some reason is making the air stick on. I got the air to stick on again by turning the constant air switch on, than off again. I than unscrewed the retaining cap on the torch, and the air shut off. I thought maybe it was a fluke so I tried it again and again and it worked every time. I would unscrew the retaining cap, and the air would turn off.

I’m still baffled trying to figure out how the retaining cap has something to do with the solenoid turning the air off. Is for some reason the solenoid staying open because the air cannot bleed out fast enough through the retaining cap?

I tried to get the air to stick on again only this time with the retaining cap off. I could not get it to stick on. The air would shut off every time like it is suppose to.

So I dove into it a little deeper. I disassembled the torch. Everything looked good on the inside. Nothing was melted, no burn marks, all looked good. I pulled out the… uhm… part where all the action happens. Not sure what it’s called, the part with the plunger. I took that out to inspect it. I though that maybe I had a week spring that pushes the electrode against the nozzle (where the pilot arc strikes). I pulled the plunger out to see if maybe I had something stuck on the inside that was keeping it from closing. No dirt was found. I pulled the plunger out a little further and the O-Ring popped out. I noticed it was very stretched out and loose. Other than the O-ring being stretched out, I could not find anything wrong with the torch. I squeezed the O-ring back into place and assembled everything back together, consumables are installed and retaining cap is screwed on. I turned the “constant air” switch on, than off again… and the air stuck on.

I’m not sure where to go from here. I really don’t want to spend the money to but a new torch, when the torch may not be the problem.

I’m halfway don’t with a customer’s order of 100 parts. It’s a pain to have to sit there and bleed the air from the machine after each cut in order to start the next cut to start. 6 pierces per piece, and 50 more pieces to cut. That’s bleeding the air off 300 more times.


I’m really hoping someone could help me out

Thanks!!

It still likely could be a solenoid spring. I've seen something similar with another customers unit and it was a spring that needed to be stretched in the solenoid just a few thousandths. Next time it sticks, try slapping or tapping the unit toward the back. You may have your supply pressure too high as well. Make sure it is no more than 90, and 80 if possible. Turn your torch down just a little.

Thanks. I'll give that a try tonight and let you know how it goes.

Mark, What voltage is the coil in the solenoid?

Cpierce May be able to replace with something sourced locally.

I finished cutting out the parts last night. I set the air pressure at 65psi. It cut fine for about the first 6 pieces (30 on/off cycles) than the air would stick on again. I did what you said and smacked the side of the machine and the air shut off. So I’m guessing it’s the solenoid that is sticking. I bought the unit in the beginning of 2011 (I think). What should my next course of action be? Could I adjust it? Could I replace it? If there a way to clean it? or does this need to fall under warranty work?

It's like there is some moisture, dirt or corrosion in the unit's solenoid or the spring is a little short. You can easily access the solenoid and disassemble it and clean it. Stretch the spring just a few thousandths, and you should be back and going in 15 minutes.

I was hoping you would say that. Quick and painless I hope. I’ll clean it up within the next couple days and let you know how it works from there.

Thanks again,
Chris