Thread: Miller plasma fault light problem

i have a spectrum 625 plasma machine that is giving a Temp fault light . when i turn the machine on
from cold @ around 55 deg - the air and cup lights go out , but the temp light stays lit and the thing won't
start . if i leave it idling long enough , the light will go out and i can get it to spray for about 2 seconds before it quits and the temp faults again.

i haven't used the machine in about a year - are there relays, contactors or sensors i should inspect
when i pull the covers ? i have the miller schematic, but it is more of ageneral wiring diagram and
of little help to me.

It probably has a mechanical thermal switch somewhere in there that could use replacing. Think of where it would get hot and look for a little thing with two wires. Could be a metal can, could be a little tube, could be bolted to a transformer or heatsink or in the airflow.

if its like a hypertherm, they do that when the contact tip gets worn out and it will prevent it from starting. it protects the cable that way.

new cup, cone, swirl and tip. cable tests good for continuity.

ya could be anything electrical internally. failures happen easier when colder. need someone good with electronics to test all the circuits related to it.

it works fine now..... repair procedure #2 ........ i just left it on for 5 days straight..
. now it powers up and cuts like a champ. must have been damp in there.

Originally Posted by tnmgcarbide

it works fine now..... repair procedure #2 ........ i just left it on for 5 days straight..
. now it powers up and cuts like a champ. must have been damp in there.

did you dust it out with compressed air ?

many times... but removing the panels, it was spotless in there. no grit, dust mites or cobwebs.