electric welders

Hi everybody, in regards to electric (arc welders) I have been looking into this subject and have found that it is recommended to twist the positive and negative leads together, secure the earth as close as possible to where the area is being welded, move the machine as far away from you as you can, don't lean in too close to the arc and have somebody near you that can turn the welder off if anything goes wrong...... My question is have anyone out there actually used an arc welder who has a pace maker fitted and is there any thing else that you can add to the above items, I only use the welder once or twice a year, when I break something, but I don't want to break myself..???

12 Comments

Electric welder & generator

by JerryG - 2013-12-04 03:12:32

I have an arc welder which I use periodically and I also have a diesel power generator.

I have used my welder a couple of times since PM implant with no ill effect. The only precaution I have taken is to make sure the welder isn't too close to me (>1 metre away). I think the danger to the PM is the magnetic field of the welder transformer rather than the arc itself. I periodically have problems with elephants breaking things that I have to weld to repair and as my game farm is 55km from the nearest village, I have to fix things myself or they don't get fixed.

I have had to start my diesel generator at least 4 times since PM implant and again, haven't suffered any ill effects. My electricity often goes out here due to the long, open power lines and the fierce electrical storms we have. It is very hot here and without electricity I not only don't have air conditioning but my refrigerators start defrosting very quickly and as I have electric pumps in my boreholes I may run out of water if the outage lasts too long. The generator perhaps even bigger magnetic fields than an arc welder. I am only ±1 metre from the generator when I start the engine but I haven't had any problem.

I guess I have to just keep on fixing!

JerryG

Arc Welders

by donr - 2013-12-04 07:12:51

We have several active members who arc weld successfully.

Pace-man has it right about protecting himself by twisting the leads together, keeping them as far from the PM as possible & establishing the ground (Earth) as close to the arc point as possible.

IF your welder is a true DC current device, that should give you pretty good protection. Steady state magnetic fields will only put your PM into its TEST mode & it will come out as soon as the field dies & all will return to normal. If it is a device that generates a square wave current for the welding, it's a different colored horse (or is that a Zebra?) & you want to be a bit more leery of it. There is someone else here who does auto body welding successfully & safely. Perhaps he will show up after the US mid west awakens. Cannot recall who he is, but he has posted several times.

IIRC, it is the MIG & TIG systems that are more dangerous for devices.

BTW: The arc generates a really intense, broad RF spectrum. Back in the infant days of radio transmission, that's how the RF energy for the transmitter was generated. A humongous arc was struck & kept going while an electric filter selected the particular frequency needed for transmission.

Your PM is adequately shielded against RF interference, so that is not a significant problem.

From what you two say. unless you are going to get a job in a shipyard or boiler works welding submarine hulls or big pressure vessels, you should be safe.

This should be a reasonably decent starter discussion. I'm not a welder, just an EE.

Generators - good, modern generators are well designed to control loss of magnetic field out of the generator case. So that should not be a real problem. Is it a DC generator or an AC Alternator that you have? On larger output devices, don't you usually start them up w/ the magnetic field unexcited so the engine is not trying to lug the generating part along while not at full operating RPM?

I'd say that as long as you do not hug the case of the generating section, you're safe. It's only when you get into huge commercial generating stations that the stray fields will affect you. We have several members who have visited hydro-electric dams & felt the effect, but there the electric currents are measured in the thousands of Amps - what are you talking? a couple hundred at most?

I'll give you a benchmark from a personal experience- 240 Volts, 60 Hertz; 30 Amps at less than 6 inches from my PM put mine into TEST mode & scared the daylights out of me. When I had moved less than 6 more inches (15 Cm) away from the cable, the effect went away.

Don

25 KVA

by donr - 2013-12-04 08:12:22

Peanuts as gensets run! Just don't run out & hug the Alternator & you should be just fine.

Jerry, what I was asking about was whether or not the alternator starts putting out power as soon as the engine starts running at full RPM. Or - do you have to separately throw a switch to excite the field windings to start power output.

At least you don't have to synchronize the phases w/ the power company!

Why do you need 3 phase? Too far back in history for me to remember - the 25KVA - I assume that it splits into 3 for roughly 8 KVA per phase, which comes out to about 20 Amps per phase. Less than my water heater power that shut my PM down into its TEST mode.

Don

Welder & generator

by JerryG - 2013-12-04 10:12:40

My welder is a proper DC device so I guess that should be fine even at close range. I agree that I am not working as a production welder; I fix things that are broke occasionally but I doubt I actually weld > ½ hour a month.

My genset is actually an alternator set is it generates AC power. It certainly isn't big; 3-phase 380v 50hz with maximum running output of 25kva. I don't have auto switching on it i.e. the genset doesn't start automatically when the mains power dies. I have to go to the control panel on the side of the unit and press the starter button, wait for it to reach operating rpm then put on the switches to feed my distribution boards. Similar procedure when my pilot light tells me that the utility power supply is back. I would like to have auto switching but it costs almost as much as the genset cost me and I didn't think it was worth it.

Thanks for the inputs Don.

JerryG

Doesn't matter...

by donr - 2013-12-05 11:12:39

...where you are for input voltage & frequency.

Probably 50 Hz, since you are in Australia. It all goes into a transformer & some sort of rectification device and/or wave shaping device that gives you the 100Amps output. If it's a simple minded arc welder, probably a DC output. I assume you do principally sheet metal bodies. Perhaps some frame members, but nothing like a submarine hull.

I cannot recall who our really experienced arc welders are, so cannot give you an address for a Pvt Msg.

Keep the Amps down & the distance from your PM up & you are OK..

Don

ac-dc ?

by pace-man - 2013-12-05 12:12:00

not sure if my welder is ac or dc , the welder is pretty old, I know it is 240v and our power supply is ac I mostly weld with the amps set around the 100 amp sometimes more and sometimes less, it all depends on what I am welding , I am a bit like JerryG , where I do most of the welding is a fair distance from any where, however I must admit that I haven't had any problems with the elephants. That sure does sound interesting. Rick

Genset

by JerryG - 2013-12-06 02:12:46

Don my alternator is generating full power when engine reaches operating rpm and I only need to switch the power utility off and the generator supply on (I don't want to feed power back into the grid!). I get a little over 30 amps per phase and I agree 25kva is comparatively small but it is enough to run my pumps, air conditioners, lights, computers and the electric fence around my residence. I need 3-phase as I have quite a big pump in my main borehole which has to have a 3-phase motor on it (3.7kw).

Rick my farm is in a private game reserve which is ultimately part of the Greater Kruger National Park and we have a plague of elephants at the moment. The younger bulls which we have a lot of are very destructive and they not only push over lots of large trees but they also rip up water pipes and all sorts of other things that may take their fancy!

JerryG

Ah, 3 Phase - that's an elephant of a different color

by donr - 2013-12-07 09:12:19

That's the different colored elephant.

If You have all three phases running in the same wire trough you can get some pretty big magnetic fields. except trhat they are 120 degrees out of phase w/ one another - would give you a rather weird wave form for the field.

30 Amps is nothing after 6 inches distance from the cables - I can attest to that!

Jerry, can you give us geographical coordinates so we see you on a Google Map? That would be interesting.

Did you ever see the post & resulting thread by the man in South Africa who got fried by his own electric fence - it was in an area where people & large animals collide. But no elephants. I asked him how he managed to get such a jolt - he was standing on a wet asphalt parking area in bare feet or some such foolishness.

And I think we have problems w/ the burgeoning population of 200 lb black Bears...

Don

Co-ordinates

by JerryG - 2013-12-08 02:12:17

GPS co-ordinates are 24 08.228S 30 55.570E; that is the location of my 'camp' as we call it.

I have argued with my fence on a couple of occasions and it isn't a pleasant experience. The fence operates at 10000V / 12amp but fortunately it pulses otherwise that voltage and current would fry you. The high voltage means there is a field around the wires and you can get shocked without actually touching the wire. I told my cardio after my electric cardioversion that he could have saved me a lot of money if he had suggested I touch my fence to shock my heart back into sinus rhythm :-)

I have to have the fence around my camp otherwise I could one day be enjoying a sundowner and find a leopard on my lap!

JerryG

A quiet place in the country

by pace-man - 2013-12-08 06:12:32

Hi Jerry , I had a look on Google earth to see where you live, you sure do like to get away from it all,I don't think you would have any trouble with your neighbors starting their mowers up early on a quiet Sunday morning, but their pets sound like they are a bit of a problem. Thanks for your input about electric welders, it sounds like I will be able to use it with the right precautions.
Where I am staying at the moment is in northen Australia, the state is called Queensland and the town is Clairview, it is right on the edge of the ocean,with lots of islands and plenty of fish to catch, we do have crocodiles here, but they are not much of a problem, I think the sharks are more of a problem. I dont even have a fence here let alone one like you have, sounds like you could cook a steak on it. Rick

Do it yourself Cardioversion

by donr - 2013-12-08 10:12:30

Jerry: That would literally make your hair stand on end! That takes one heck of a power supply. At that voltage, it would take a lot more than a pair of leather or rubber soled boots on dry ground to protect you from shock . Wet ground could make it fatal.

Don't the big cats leap the fences? Or do you have them high enough that they will not jump.

Thanks for the coordinates - I'll look it up.

Don

Jerry is alone?????

by donr - 2013-12-09 09:12:48

Rick - Jerry & I live right downtown compared to where you are.

Is that a big mud flat right at the shore? Looks like it.

Here I thought that there were no sharks where you live because the Crocs chased them all off.

Don

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