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  • blown boards and power line voltage spikes

    Is it possible welding machine boards are being destroyed due to powerline voltage spikes and lightening strikes? Would a lightening arrester or a surge protector help save boards?

  • #2
    Very possible. I never leave a welder plugged in when not in use. If it's hardwired, at least turn off the wall switch/breaker. Not as good as unplugging, but better than nothing. And the lightning strike may not take it out right away, but it may fail months or years later, and you'll have no idea it was a lightning problem.

    Had a case with 4 good-size three-phase commercial air conditioning units on a single building a number of years ago. Lightning strike took out the control board in one unit; others survived. Replaced the board and all was well--for a number of months. Over the next number of months/years that same unit has required replacement of the run capacitor on the condenser unit fan, the compressor contactor, and the air handler fan contactor. All at separate times over a very long period, but all on the same unit. The other three units have not had a single problem. Just doesn't feel like a coincidence to me. I call them the "walking wounded" parts.

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    • #3
      Good information Aeronca, thanks, I have my 16' long power cable with a 220 receptacle box hard wired to an On and off switch box mounted on the shops wall.

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      • #4
        With lightning there really are no rules...it does some weird stuff. It can jump from the ground to a cloud, so I'm pretty sure it can jump the gap in a breaker or a disconnect switch, but either of those is much better than leaving everything connected. I unplug my welders just for this reason.

        As a kid I was home alone after school one day and had the radio going when a storm developed. We had a strike very close to the house....like within yards. Seconds later the radio made a crazy noise, quit working and then smoke came out of one of the speakers. A few days later I was watching TV when it suddenly shut off but had three green lights in the middle of the screen. We had a couple of other things die over the next few months and I'm sure all of that was from the lighting strike. I joked with my parents that the house was possessed!

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        • #5
          I'm the last property on the line, which I was told is not good, we have lost a couple VCRs and appliances, and beautiful short wave radio due to lightening hitting our line. I think I'm going to unplug the welders from now on, thanks for your interesting and valuable input.

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          • #6
            I was told and I was always told are not very reliable. An expert named Westom shows up on GJ about lightening. If rthere are problems there is likely a problem with the install. It took me a bit to really get a grip it was the phukkin phone company and their half baked install and after I fix the ground according to 880 of the code never another strike in the buiilding and one I had about 15 yrs ago took out the suppressor like it should.
            Lots of electronic guys seem to have trouble with grounding, nit sure why but,,, a suppressor is no good without it.
            I have been at strikes, not too long ago the insurance guy at the neighbors and they jump to the fact the well as damaged,,, duh but a bluind sparky could see it hit an ungrounded shed, folled the extended circuit it was on,,, yes the TVand other equipment damaged on it but the ungrounded shed, the broke rods at the service pole and the olny ground left was the equipment ground on the well. No,,,, it didnt "hit" the well, the well was on the receiving end.
            I used to unplug the phone modem when they were internal, hooked to a grounded machine but the new are not. Now that I grounded the phone service correctly havnt had a blown power strip for 20 years, no more strikes. I spose there could be some logic to end of the line but I kind of doubt it,,,,, number 1,,,, best thing you can do, absolutely best is good ground electrodes and a suppressor at service. Unplugging the welders wont do a thing, never seen one hit and while they are grounded equipment is not grounded to them, huge difference. Wont do anything to protect them except extra work and give more false security at the expense of real, all it will do is give you a warm feeling. I spose that is comforting, makes it real.

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            • #7
              Welding machines have a switch, disconnects all ungrounded conductors. Since the grounded conductor on 120V models is grounded at service no place for it to hunt so to speak down the line to the machine and on 240V models it doesnt even have that wire. Has a switch disconnects both poles and ground wire not in series buit back to the service there is no reason to disconnect. Nothing in the instruction manual says,, unplug machine except for service.
              I tend to think power surges and voltage "spikes" not sure whhere those cpme from are largly created by those making the equipment and paraded over the internet,,, not so much a problem till it came along.

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              • #8
                Lightening is trying to find the earth. Its not looking for your equipment. If it cant because there is an open in the grounding, it the electroded not making contact , building not grounded then it is looking for a better ground. Just like the example I post up earlier. Neighbor taps the outlet on side of a mobile and runs a circuit to a tin shed on wood poles, lightening hits it and can actually follow that circuit back thru the place, finally found it down the well. If the electrodes would have been in tact at service it would likely have terminated there. Its not really hunting live or ungrounded conductors its looking for ground and the live conductors are disconnected by switch in the machine.

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                • #9
                  I can see a problem on big AC units, lots of stuff to hit, all the metal piping etc and never know the state of grounding which is the first the real expert checks. Welding machine slightly different as its not interconnected to elaborate system and not on the receiving end of a hit to the chassis.
                  and you'll have no idea it was a lightning problem.
                  No idea it was either.
                  Also,,, the "jump" a gap in breaker or switch thinking is faulty to some extent, Where would it go it if did so to speak? spose it could try to find a ground within the machine but the potential is not really there and it has to "go" somewhere and not thru an open switch.
                  With lightning there really are no rules
                  Yes there are.
                  Last edited by Sberry; 08-07-2021, 06:31 AM.

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                  • #10
                    You are absolutely free to hold your beliefs, but will unfortunately bear whatever consequences may occur....and generally, as stated previously, when the failure of the walking wounded parts occurs months or years later, most people will not tie it back to an electrical surge event. But there is often a connection. Equipment grounding conductors and ground rods/water pipe systems are useless as grounds when they themselves are potentially raised to a potential of multiple thousands of volts for several microseconds or even milliseconds by lightning currents flowing through the earth.

                    G-man summed it up very well in his first statement above--as most of us understand electricity, "with lightning there are no rules". As to the manual not telling you to unplug it--these occurrences don't happen every day, but if they do, the manufacturers are more than happy to sell you a new welder--no problem for them at all. Once again, it is all about risk/benefit. If I can potentially save a multiple-thousand-dollar repair on an expensive welder, seems like unplugging it is pretty cheap insurance. Not saying every welder left plugged in is going to be damaged--that would just be a dumb statement--and there are probably hundreds of people who do it all the time and have never had a problem. But I for one choose not to place myself at risk to be part of the small percentage that don't get away with it.

                    Electronic equipment can be toasted even with just the ground wire connected--None of the normal rules of switches, grounds, etc. apply very much when you are talking about tens of thousands of volts and tens or hundreds of thousands of potential amps being conducted through the earth, ground rods, etc. Switches can be absolutely useless. Every switch sold with a UL listing shows its rated voltage and current. The ratings are no where near the voltages that can be induced in a power line for a few microseconds by a lightning strike--and a few microseconds is plenty of time to blow a chip.

                    Those huge insulators, and their physical separation from each other by five or six feet or more in electrical substations are not just for show--high voltage electricity has the ability to "reach out and touch" all on it's own--and those substations are nothing compared the energy in a lightning strike.

                    I know of a case a number of years ago where a car accident broke a utility pole, and the high line voltage wires came down and connected to the drop to a guy's house. This house had been wired in the 1930s or 40s, so apparently the insulation on the drop wires was pretty shot-but maybe the voltage was so high it didn't matter. At any rate, the voltage was high enough to jump every switch in his house, and everything came on for a second or two. The house required required complete rewiring, and everything electrical required replacement. And that was no where near the voltage possible from lightning. The house was old, and they just tore it down and there is now a RAM truck dealership in that space.

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                    • #11
                      Originally posted by Aeronca41 View Post
                      You are absolutely free to hold your beliefs, but will unfortunately bear whatever consequences may occur....and generally, as stated previously, when the failure of the walking wounded parts occurs months or years later, most people will not tie it back to an electrical surge event. But there is often a connection. Equipment grounding conductors and ground rods/water pipe systems are useless as grounds when they themselves are potentially raised to a potential of multiple thousands of volts for several microseconds or even milliseconds by lightning currents flowing through the earth.

                      G-man summed it up very well in his first statement above--as most of us understand electricity, "with lightning there are no rules". As to the manual not telling you to unplug it--these occurrences don't happen every day, but if they do, the manufacturers are more than happy to sell you a new welder--no problem for them at all. Once again, it is all about risk/benefit. If I can potentially save a multiple-thousand-dollar repair on an expensive welder, seems like unplugging it is pretty cheap insurance. Not saying every welder left plugged in is going to be damaged--that would just be a dumb statement--and there are probably hundreds of people who do it all the time and have never had a problem. But I for one choose not to place myself at risk to be part of the small percentage that don't get away with it.

                      Electronic equipment can be toasted even with just the ground wire connected--None of the normal rules of switches, grounds, etc. apply very much when you are talking about tens of thousands of volts and tens or hundreds of thousands of potential amps being conducted through the earth, ground rods, etc. Switches can be absolutely useless. Every switch sold with a UL listing shows its rated voltage and current. The ratings are no where near the voltages that can be induced in a power line for a few microseconds by a lightning strike--and a few microseconds is plenty of time to blow a chip.

                      Those huge insulators, and their physical separation from each other by five or six feet or more in electrical substations are not just for show--high voltage electricity has the ability to "reach out and touch" all on it's own--and those substations are nothing compared the energy in a lightning strike.

                      I know of a case a number of years ago where a car accident broke a utility pole, and the high line voltage wires came down and connected to the drop to a guy's house. This house had been wired in the 1930s or 40s, so apparently the insulation on the drop wires was pretty shot-but maybe the voltage was so high it didn't matter. At any rate, the voltage was high enough to jump every switch in his house, and everything came on for a second or two. The house required required complete rewiring, and everything electrical required replacement. And that was no where near the voltage possible from lightning. The house was old, and they just tore it down and there is now a RAM truck dealership in that space.
                      Last night a thunderstorm caused our power to go out three times. luckily each time it came back on. None of my machines are hard wired to a circuit, so for me it's just a matter of pulling a machines plug and eliminating all chances of lightening damage.

                      Thanks again guys for putting things in understandable terms.

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                      • #12
                        I read home built three phase converters which aren't balanced properly can send dirty power down line, is it true and can anything be done to check for it and correct the problem? Would unbalanced three phase power effect single phase power too?

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                        • #13
                          zillions of peices of equipment run every day thru all lkinds of weather and you are gonna be that guy has his welder ruined by lightening, and even worse may never know. Secondly welders are rather robust in this regards. I have had damaged equipment. It might have hit the circuit board who knows but the real fault was the ground. We are not grounding other equippment to welding machines ,,, we are grounding them to the service and relative to other equipment.
                          My explanation certainly is suspect, my real knowledge and expertise limited at best but I have asked the real expert or 2to splain to me how this all basically works and why and in the process he happened to mention that electronic guys can seem to find a way to put a spin on it as their electric is special from others but it takes a bit to get ones mind around this and not sure I really can explain it.
                          I understand most of you know more about electric than I ever will,,,, absolutely no debate but this is rooted in code and lightening prevention and well studied.
                          Last edited by Sberry; 08-07-2021, 12:42 PM.

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                          • #14
                            I cant tell the tech data but the idea I get that supression is to shunt it to the earth as close to the event as possible. Absolutely some events so catastrophic as unavoidable, hurricane makes sense to unplug etc but most not practical, one reason they put a good switch in the first place.
                            Something Keis said made a lot of sense,,, said we add ground rods to the poles of the parking lot lights at the casino. Its not in place of the egc but to divert strike there vs it being carried back to the source.

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                            • #15
                              Originally posted by tackit View Post
                              I read home built three phase converters which aren't balanced properly can send dirty power down line, is it true and can anything be done to check for it and correct the problem? Would unbalanced three phase power effect single phase power too?
                              I think I can understand what they're talking about but I am not knowledgeable enough in that area to offer any opinion that I could say has much basis in fact. I do know that the power company doesn't like it when you mess up the balance across the three phases significantly, but again, not an area of my knowledge.

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