Better to leave welder on or turn on/off?

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In my furniture making biz I mostly do lots of short welds, with 5-10 minutes between rounds.  I've been turning my welder off and on between, but recently thought it might be better to leave it running.  Thoughts?I'm using a Millermatic 175 that was recently given an excellent bill of health from my welding supply shop.Thanks.Jobe Fabrications
Reply:IMOYou should be able to leave a Mig machine running at idle as the transformer isn't energized wasting electricity, just circuit boards and cooling fan are powered.
Reply:Originally Posted by drujininIMOYou should be able to leave a Mig machine running at idle as the transformer isn't energized wasting electricity, just circuit boards and cooling fan are powered.
Reply:Originally Posted by shovelonTransformer welders with caps are power hogs at idle.
Reply:One of the most stressful parts of electronics (things like the stereo or computer) is the constant thermal cycling when its turned on and off.   Turn it on and it heats up - expands.  Turn it off and it cools down - contracts.  The constant expanding and contracting can (and does) eventually lead to the break down on things like semiconductors.Transformers - about the only thing that can go bad is the insulation around the wires.  I suspect corrosion at terminals might affect things.  If the transformer gets too hot, the insulation (which is nothing more than a layer of clear paint - typically) could melt and a wire or two could touch - not a big deal, but the efficiency goes down.  Too many of these shorts and it wont work at all.Capacitors are a bit different.  There are different types.  The insulators they use inside are subject to overheating.  Once a capacitor shorts out, it is done.... ofter though it can heat up and litterally explode if it has a short.  By explode, i mean physically pop - usually the ends.One concern with capacitors is voltage.  A capacitor might be rated at a couple hundred volts (how much voltage before it breaks down and acts like a short), but you have to understand that when you through the power switch (on -or- off) you are creating surges in the electronics which, depending on their design, could be susceptible.In one attempt to save a power switch on a piece of electronics (a 'VME' rack if you must know), we used the switch on a power strip to turn it off and on.  And this equipment had to be rebooted often so we used the power switch often enough....   Until one day (call it a month - 100-200 restarts) it starting making noise - like arcing of a welder...  Turns out it was a capacitor in the high dollar, high current power supply that popped.  $1000 later (rip off prices - but we needed an exact fit) and we were up and running again.  FYI, VME chassis/racks can hold 21 separate computers and must feed 5volts to each.  So its 750 W total; 5V at 120A; 12V at 12A; -5V at 8A; and -12V at 8A)Personally I would turn it on once per 'session'.  Do yourself a favor and point the front of the machines to the door of the shop.  So when you leave at the end of the day you can see from the door you powered them off (and presumably turned off the gas...).  Darn inverters are so quiet.  Note: the 350P makes no noise at all unless its running hotCon Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Leaving a MIG run gives the fan a chance to do it's thing. On hot summer days those internals need all the help they can get, especially on the MM175. I've got one that I turn on and leave on unless I know it's going to be awhile before iI get back to it or a chance of forgetting later. It's got one heck of a lot more fan time than arc time for sure. Almost ten years now and the fan has got a little wobble to it. Fans are cheap in the scheme of things. Of course it's not my go-to machine anymore so that wobble should last for another ten now. Maybe pull it out and give it a drop of oil some day when I'm bored."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Thanks for the feedback. I should add that I mainly use this only nights for a max of 3-4 hours at a time. It's not on and off all day long.Jobe Fabrications
Reply:without speaking to your welder:It is a general truism that electronics are way far  better off if left running than cycled on and off.However there are other considerations such as taking for granted or forgetting  the fact that a welder is powered up.  In the case of a stick rig, that means the electrode is available to complete a circuit to anything or anyone that is also grounded to the work clamp however fleetingly.I'm curious: What kind of welding are you doing  in a wood shop?   Is there sawdust? Which raises a question for me:When the electrode holder  in a stick rig or a TIG electrode holder is ready to use  how come the operator doesn't get zapped when he is putting a stick in the holder?I usually get zapped a little when I accidentally  touch  the 120 VAC hot line  in the residential wiring. I believe that it is because no matter what else there is usually some kind of path to ground however weak.Last edited by Raul; 04-15-2013 at 05:59 PM.Hey~!! It's a hobby. It's not supposed to make sense~!!
Reply:I think my Weldpak 100 owners manual said to turn off after cool down to save fan life. IMHO, do what you think works best.
Reply:Sold a nice Clarke 135 MIG to a guy.  He ran it a day or so then had problems with sputtering & etc.  Best I could tell, he ran it too hard (having fun with a new welder) and then shut it down immediately after a long session.  From what he said about a visual inspection, the diodes appeared to have cooked.  Let the welder run a bit.  Worst case is you waste a wee bit of electricity and the fan wears out a bit sooner."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by Raul...When the electrode holder  in a stick rig or a TIG electrode holder is ready to use  how come the operator doesn't get zapped when he is putting a stick in the holder?...
Reply:Originally Posted by papaharley03The ones with power factor correction caps are. Since the OP referred to a MIG welder, I think his idle current draw is not too bad on a MM175. As was stated, only the cooling fan and PC boards are drawing power at idle.Papa
Reply:Originally Posted by MikeGyverTig arc voltage is too low to shock you,
Reply:Truthfully I forget mine is on until I sit down for a pop or snacks, then it starts to bug me.  That's usually when it gets turned off Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by RaulI just know that somewhere on the floor is my  jaw.  Gimme a minute so I can pick it up and I'll respondOk I have recovered from the shock of what you said. Be still my heart. Maybe it was the word "zap" ?  Did I mislead? I am confused.  I mean Really Honkin confused big time.I though it was not to volts that killed people, but the Amps and the Amps were purdy durn high in the welding process.  It's the dirt nap zap of which I speak.All those howling amps  just looking for something to do.  I read somewhere that it only takes a milliamp to kill a person if it hits him right ( or hits him wrong, might be the better way to say it).Am I making any sense? I feel like Joey when they  opened the ***** cake.
Reply:Electricity looks for the shortest path to ground, as long as that path doesn't go through your heart you have a good chance of living.
Reply:12 volts in not enough potential difference to push ANY amps through the high resistance of your external body, maybe if you stabbed copper paddles into your heart then hooked them up it would mess you up...A typical TIG arc is around 16 volts DC.
Reply:I don't think it's volts OR amps that kill you so much as it is ENERGY (kiloWatt-hours).It takes a certain number of kilowatt-hours to cook a potato, and a certain number of kilowatt-hours to defrost a human.At high voltage, it will only take some small fraction of an amp to kill you.At low voltage, it's going to take quite a few amps to kill you. (Or an awful long time.)AC, especially around 60 Hz, is generally more dangerous than DC because the polarity changing at around that speed tends to throw the heart muscle into fibrillation. It goes into spasms, working against itself like a bowl full of wobbling Jello.It also can depend on where the current travels. If it goes in your right arm and out your right leg, it might not be as bad as if it goes in your right arm and then goes out your left arm, traveling through your heart along the way.There are a lot of variables. Or so I've been told.Last edited by Kelvin; 04-16-2013 at 06:04 PM.
Reply:Originally Posted by RaulSo  (I ain't about to try this mind you)  If I placed the electrode on my arm and then grabbed the  work clamp what should I expect to happen?
Reply:Holy crap!  That is a lot of voltage to cook them like that!Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:It doesn't take much energy to kill you.  It takes rather more to flash fry you all puffy and crisp like that."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Originally Posted by KelvinNot recommended.http://www.thepadrino.com/2012/02/co...trying-to.html
Reply:Originally Posted by MinnesotaDaveHoly crap!  That is a lot of voltage to cook them like that!Dave J.
Reply:It all depends on how conductive you are. I got bit by 24v dc before when working on a boat. It hurts like heck. The current(A) is what will get you. The more conductive you are, hot, sweaty, salty - the more current you will pass. The path it takes through you body makes a huge difference and can change your life.Dynasty 200DXMiller 210 Spooly
Reply:Originally Posted by DirtyOzIt all depends on how conductive you are.Do the electronics take a  'spike' when turned on?Torchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Originally Posted by GambleDo the electronics take a  'spike' when turned on?