HP PM65 losing arc.

[SegoMan DeSigns]

The only thing I can think of is it had enough current to fire the torch but not maintain relay draw..

[weldguy]

The only thing I can think of is it had enough current to fire the torch but not maintain relay draw..

That's what I figured also. Lucky it didn't fry something else!

[John Bewick]

Well, fortunately the voltage divider output does seem to be working ok, as the Price AVHC does show torch voltage when cutting.

[SegoMan DeSigns]

Well, fortunately the voltage divider output does seem to be working ok, as the Price AVHC does show torch voltage when cutting.

[adbuch]

Well... Machine came back with no fault found. Fitted back onto table, and yes, just the same as before.
Anyway, it is now confirmed, it is not the PM65 at fault.
Thought I would try fitting a remote switch to fire the machine manually. Removed the interface cable to connect a remote switch cable onto, and thought to first just check the wiring of the interface cable plug. WELL, it turns out the person who made the interface cable ( supplied by Extreme Plasma with the Price AVHC ) had incorrectly marked the wiring. Wires marked for torch switch were connected to terminals 3 and 5. instead of terminals 3 and 4. Terminal 5 is the Neg signal wire for voltage divider.
Rewired to correct terminals, and YES it is now working as it should.
I am not going to say what I think of the person who made that interface cable, but suffice to say, it would not be pleasant.
I just hope it has not done any harm to the voltage divider.
Thank you all for your kind help and suggestions. Now I can get on with dialling in all the tool parameters etc etc.

John

John - glad to hear you are back in business (so to speak). Having a bad cable would certainly do it. So now you've got it fixed, and hopefully this experience will help you in the future should things get out of wack again.
David

[HypHyDef]

SegoMan, no, Hypertherm made no suggestion of any thing to try. They just asked for me to send picture of service sreen, and from that, asked me to contact supplying dealer to organise a warranty repair. I suspect this is the first time that a fault caused by incorrect wiring of the torch switch and voltage divider wires has been encountered, so nobody was aware of the outcome. I thought it would be of interest to post this resolution to the problem, as it shows that, if the torch firing switch wires and voltage divider wires are interchanged as mine were, it will still allow the torch to fire, but not maintain an arc, I wonder why that woud be ?

John, I'm thrilled to see you got your system sorted out, bummed that it took so long. I'm going to share your findings with the tech support team here at headquarters. Thanks for posting what the cause was here for me to forward.

[weldguy]

I am still shocked that this faulty cable problem evaded all of us including Hypertherm!