View Full Version : Plasma cutting at below freezing
02-12-2008, 11:51 AM
Hey gang, long time no see. was away from the shop for awhile and now have a 2-car garage to set up in, yay! so ive been tigging and plasma cutting happily in a huge space, until..
the temp in NYC dropped well below freezing a couple days ago. i used to hv my workshop indoors so temp was never less than 50 and equipment behaved.
but yesterday my air compressor choked and tripped its breaker tryin to start (prolly full of water/ice, so i thawed and drained it), and today my hypertherm 380 wont recognize the correct air input pressure; tho it's over 100 psi on the compressor gauge (And the machine's), the arc wont last 5 seconds before the low pressure light comes on. ideas? all i hv in there is a lil ceramic space heater so i hope it's not the temp. machine needs 60 PSI/0.4 MPa (what is MPa?).
appreciate the knowledge--
02-12-2008, 12:00 PM
Ice in the unit or the hose (take 'em inside for the night)
Moisture build up from the thawing condensation...blow it all out with dry air.
'just guesses...not a problem I've experienced down here...but it might go down to a bitter 30 tonight!!! (Was 56 last night).:p
02-12-2008, 12:16 PM
machine needs 60 PSI/0.4 MPa (what is MPa?).MPa is megapascals (metric.) 1 MPa = 145 psi.
02-12-2008, 12:28 PM
dollars to donuts your filter(s) are frozen, the wet element is iced restricting flow below that required, full pressure, low flow, makes for a low pressure light.
02-12-2008, 12:46 PM
thanks pumpkinhead, ill try that. i know there's air @ pressure in the lines but the flowthru in the filter element (im using those toilet-papery ones) might be inadequate.
****, it's snowing now. better start makin some heat in that garage :D
02-12-2008, 07:00 PM
Just wait. Shortly there will be warm moist air outside and it will condense on all the nice cold stuff.:eek:
02-12-2008, 08:24 PM
FYI, it was in fact all of those things suggested. there was some water in the compressor tanks, which decreased the space available for air. there was ice in the lines and ice in the filter element, plus the lines were on the cold floor where they could freeze. i hung them, drained them, changed the element and ran enough air through the open lines to thaw them. once everything was thawed and somewhat dried it worked fine, and no humidity!
so hopefully now i wont hv to tk my compressor in for the night..will see with my lines open and my tanks drained (and my filter case opened with media indoors to dry) if that solves the problem(s). thanks!!
02-13-2008, 01:06 AM
You will also find that in extreme cold, similar to a car engine, the oil in your compressor (unless it's an oil less type) will thicken, making it harder to start up. When it's real cold, I try not to be A. in my uninsulated shop b. not start the compressor, but use it like an air tank if necessary (I generally leave it pressurized but turned off, both at the switch and the outlet valve), and c. keep lots of wood on the fire in the house!