What the heck is a ground?

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Well I've heard all this bru-ha-ha about grounds and desptie my best efforts I haven't been able to understand what it is? Sure I've seen the dictionary.com answer 10,000 times, and all the jargon and crap doesn't make any sense to me with my simple mind. Can someone explain to me what grounds are and what they do (for example the ground in MIG welding)? Thankyou very much.
Reply:The ground (usually a clamp) is what completes the electrical circuit during a weld, allowing electricity to flow from your MIG gun (in this case), through the filler (wire) and then create an arc.
Reply:It's a large round blue marble that orbits the sun.Clarke 130EN C25Lincoln 225 AC Stick(1968)Smith O/A RigHF 4X6 Red BandsawBlack & Decker Pro Chopsaw16 Speed Drill PressSpeedglas XL HelmetHarbor Freight Stuff
Reply:Pay more attention to Enders comment  O_oBut Tommyj3 is also correct...
Reply:Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Pictures worth a thousand words of explanation.
Reply:Nice clamp David, I'll have to remember that for the next time I wear out a springy one.
Reply:I got tired of hearing an arc that wasn't where I was welding. David Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Its not called a ground clamp it's called a work clamp. A ground means there has to be a physical rod in the earth. Please correct your terminology --Gol'
Reply:Originally Posted by KeelhaulWell I've heard all this bru-ha-ha about grounds and desptie my best efforts I haven't been able to understand what it is? Sure I've seen the dictionary.com answer 10,000 times, and all the jargon and crap doesn't make any sense to me with my simple mind. Can someone explain to me what grounds are and what they do (for example the ground in MIG welding)? Thankyou very much.
Reply:The ground is what ever wire in an electrical system is connected to the earth.  By connecting it to the earth (ground) you can safely touch it.  On you welder the work clamp operates a bit different, some people call it a ground clamp, but that is no totally correct.  The work clamp and the earth ground are not connected in a lot of examples.  Confused Yet?Me!
Reply:but the welder is grounded with the plug
Reply:Originally Posted by Go1lumIts not called a ground clamp it's called a work clamp. A ground means there has to be a physical rod in the earth. Please correct your terminology
Reply:Originally Posted by paintmanbut the welder is grounded with the plug
Reply:It is actually a return or it can be the supply depending on polarity. Give it as much respect as you would the stinger.
Reply:Having a good solid connection is more important that what we call it.DavidLast edited by David R; 02-15-2008 at 06:48 AM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by daddyNice clamp David, I'll have to remember that for the next time I wear out a springy one.
Reply:In DC voltage a ground is a return path to complete a circuit.  Not to earth.In AC, the return path is called a Neutral (white wire),  The ground goes to earth to protect users from accidental shock in the event there is a short circuit or faulty insulationLast edited by Rick Moran; 02-15-2008 at 10:19 AM.Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:I qoute right from the modern welding technology book. "Te work connection, erroneously called the ground clamp, is an important part of the welding circuit."erroneouslyOne entry found.erroneousMain Entry:    er·ro·ne·ous Listen to the pronunciation of erroneousPronunciation:    \i-ˈrō-nē-əs, e-\ Function:    adjective Etymology:    Middle English, from Latin erroneus, from erron-, erro wanderer, from errareDate:    15th century1: containing or characterized by error : mistaken  2archaic : wandering— er·ro·ne·ous·ly adverb— er·ro·ne·ous·ness noun --Gol'
Reply:I've been avoiding this one. But what the heck. Lets fill in the holes and tie it all together. Some of the definitions below are not complete, formal defs, but are only to differentiate contexts. Formal definitions may be found in the NEC (NFPS, pub), in the Electrical Engineers Handbook (Dorf, IEEE press/CRC press, http://books.google.com/books?id=qP7...with-thumbnail)Warning: long postIt has been pointed out already that what is often called the ground in welding is more correctly called the work connection. This is the lead that goes to the workpiece to  complete the welding circuit (in manual welding, the circuit is from the machine to the electrode-- be it wire in MIG/fluxcore, a coated ros, or a tungsten electrode in TIG-- through the arc, through the workpiece, and through the work lead back to the machine) It may be the more positive or the more negative connection from the machine, and it is generally NOT connected to earth (safety) ground at the machine.The definition of ground in electrical/electronics varies a little with field and context, but accepted definitions include (not a complete list):Electronics:A reference point for potential (voltage) measurementA current return point in a circuit (may be positive or negative)A common reference point when multiple power sources are used (as in a computer)'Earth ground' in a device is a connection to the safety ground system. Often, this means a tie to a device case or frame for safety or for the control of EMI. It even uses a different symbol.Power systems:A conductor connected to (or the connection to) the earth for safety purposes. Not intended to carry current other than during fault. 'Earth' includes things like building structure, ships structure (in marine) airframe (in aero work), etc. and in some cases may not have any other than an incidental connection to the firmament of the planet on which most of us live.Contrast with:grounded conductor, which is intended to carry current, and is connected to ground, usually at a building entry. Often called a 'neutral' incorrectly. A neutral is often grounded, but being grounded doesn't make a conductor a neutral. Neutral: a current carrying conductor in a balanced supply system (like three phase, wye connected, or center-tapped single phase) that carries differential current from unbalance. In a 120V, single phase connection (like a standard receptical outlet in the US) the white wire IS NOT a neutral, as it carries the full return current. It is a grounded conductor. It is often (but not always) connected to a neutral from the power supply. Yes, there are still services in the US that are 120V, not 120/240. There are also services with no neutral (240V delta corner grounded, for example)How this applies to welding sources:In welding, the workpiece is often connected to earth ground via an incidental path (through the welding table to a building frame, or the workpiece might be the building frame itself, or the hull of a ship in water, or...), so the leads from the welding machine are NOT connected to the earth ground at the machine. They are said to 'float'. This reduces the risk of a short circuit through the welding leads and (much smaller) ground wire from the power supply to the welding machine. (anyone in the electronics industry has probably cooked at least one hunk of coax or smoked at least one power cord by connecting gear with different grounds and shorting though the grounding system. Oscilloscope leads are the loss-leader, in my experience. The only reason I keep an old tube unit with full-floating inputs around)Some multiple sources (4-paks, 8-paks, etc) connect all of the work leads together and to the mounting frame, so the welder needs only concern with one lead. The return for all machines is common. There are various ways of dealing with the need for changing polarity: many machines have a switch, some machines the leads must be manually swapped (not fun when the work lead connection to the frame of the 8-pak isn't long enough to reach), and a few can't have the polarity swapped at all. Here, the work lead is also ground (earth ground), since it is connected as such at the machine.The safety ground for a line-powered machine (like a welding machine) should follow the same path as the power leads themselves (this is VERY clearly spelled out in the NEC) to insure that, in the case of a fault, the protection devices will trigger rapidly and to reduce ground loop currents between interconnected devices (among other reasons). There should NOT be but the one connection between the grounded current carrying wire and the safety ground (usually at the service enterance), or ground loop currents are more likely. Driving a seperate ground rod or connecting the machine frame to the building structure INSTEAD OF using the normal safety ground wire should NOT be done. Making additional connections between the machine and ground (such as running a wire from the machine frame to the building structure) requires a good bit of consideration, in particular as to the maximum loop current that may flow in the ground loop created, and the path that ground loop currents may take (Can excessive heating occur in the case of  a fault? Will magnetic fields be produced that may be a problem? Can external magnetic fields cause excessive ground loop currents? etc), which is really a job for a specialist, which I am not.Story time: Once upon a time, I was working in an older structure, with riveted and bolted connections all over the steelwork. The electrical was a bit dodgy in the first place, and it had been bodged over the years by a wide variety of 'experts'. Many of the recepticals had no ground wire, and the conduit was often improperly bonded. Some had been wired with a single wire, using the conduit instead of a 'white wire' (really bad practice... as far as I know, never legal). Found one the hard way, by smell: I guess the conduit had finally lost the last vestige of good contact at one of the joints, as a bolt at one of the purlin connections became the current carrying conductor. Got hot enough for many, many years of dust and crud to start smoking, while one of our people cursed the handheld grinder that was no longer getting enough power to do any work under load.Lessons: Some people shouldn't do electrical work; check the bonding on conduit and EMT; always run a ground wire in the tubing, even in the tubing will do the job; The bolted connections are not designed to carry current: the paint on the steel is an insulator; even the 8 or 10 amp draw of a grinder is enough to get a 1/2" A325 bolt pretty hot
Reply:enlpck,Well put.Me!
Reply:Originally Posted by Go1lumIts not called a ground clamp it's called a work clamp. A ground means there has to be a physical rod in the earth. Please correct your terminology
Reply:Originally Posted by BurnitI'll bet your a riot at parties
Reply:Originally Posted by Me!The ground is what ever wire in an electrical system is connected to the earth.  By connecting it to the earth (ground) you can safely touch it.
Reply:Originally Posted by tommyj3It's a large round blue marble that orbits the sun.Originally Posted by BurnitI'll bet your a riot at parties