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04-04-2014, 08:02 PM #1
ot-need advice on overheating little giant coolant pump..
I have a little giant coolant pump hooked up to my tig welder. It is in a 5 gallon bucket and circulates water and antifreeze thru the welder and tig torch.
It has worked fine for almost 2 years. Now all, of a sudden it is running hot.
The pump housing itself is getting hot to the touch.
When it gets hot it starts trickling water instead of pumping .
It my have some clogs ( that slime stringy stuff in the coolant ), up in the torch hose somewhere.
Do I need more capacity? Maybe 25 or more gallons?
I cut a small slit in the hose that sprays the motor, and it seemed to help.
The pump is always completely submerged and the impeller turns and isn't bound up or anything.
Any suggestions are appreciated.
04-04-2014, 08:14 PM #2
Most all pumps like that won't overload the motor even if you deadhead the flow. Have you checked to see if the shaft is tight and the motor bearings possibly need lube? A lot of those motors use sleeve bearings and have provisions for oiling. The fact that the flow goes to a trickle when it gets hot is indicative of the motor slowing down.
04-04-2014, 10:56 PM #3
Good idea to take it out and sit it upside down overnight to oil the top bearing. They often lose a little oil over time and the top bearing runs dry. I would unscrew the plug and add oil as needed. No idea on where the oil level should be.
04-04-2014, 11:59 PM #4
I fought with this issue on a Syncrowave 250DX. The welder was acquired before I started working at the plant in question, and it was filled with tap water when new. Fast forward a couple of years and I'm pulling my hair out over the flow-visualizer paddle wheel stopping from time to time. Slime in the tank. Emptied and cleaned the tank, a little better. Spent a couple of hours piping compressed air forward and back thru the torch. Ordered and installed proper anti-algae anti-freeze OEM coolant. Paddle wheel still was slow to almost stopped.
But then one day, I was doing a "hot" weld where I need a lot of penetration, with a lot of pedal and I hear boiling a lot of boiling, so I stop, but it was too late, I blew out the sidewall of the water cooled jumper (the red hose in this case with the electrode wire inside it). Ordered a new one, I cut open the old one. The slime was literally clinging to the electrode wire for the several inches I cut open, the slime obviously was impervious to the attempts to remove it. The new watercooled jumper was the answer. The paddle wheel spins like mad, always, it now has the proper coolant and I don't think I'll have to mess with it for awhile.
So my free advice, get the low conductivity anti-algae coolant. Buy another water cooled jumper. I think your pump will get a lot happier
04-05-2014, 08:42 AM #5
Thanks for the info guys. I am going to to just put a straight hose on the pump and let it run and circulate water back into its bucket.That will eliminate the restriction of the torch hose.
These litle giant pumps are oil filled, so I just assumed they received plenty of oil from that.
I have 2 old ones from a previous place I worked. They threw these out for same problems, but were coolant pumps in lathes.
Tearing on of these apart will tell me how to fix/oil the bushings.
I will follow up and let you know how it goes.
In the mean time I'll turn this one upside down until I need it, and maybe it will oil it.
04-05-2014, 10:22 AM #6
We have a cpl small LG pumps that we use to transfer some coolant from a drip pan back into the tank on a mill.
But the pump got to where it didn't want to werk, yet it seemed to run fine. New pump solved the problem.
Some time later the new pump started dooing the same.
Now my BIL is pissed, and jerks one apart, and finds that the plastic impeller was just pressed onto the output shaft, and the coolant must have softened it up? He cleaned and dried it and put it back together with SuperGlue or Loctite, or ??? and it has been fine since. Roughing up the shaft a bit may be helpfull as to give the glue something to bite onto as well.
But if it is getting warmer than normal, I would look at restrictions first.
Think Snow Eh!