If you have a 25' or longer torch lead, should it be uncoiled when welding ? Just wondering if the magnetic field would cause problems.
Printable View
If you have a 25' or longer torch lead, should it be uncoiled when welding ? Just wondering if the magnetic field would cause problems.
I worked with an electrical engineer for a long time and learned a few things. This is my opinion but as long as the leads are away from the piece you are welding the field should not be a problem. I would not leave the coiled next to the welder though. I would think it could over time mess with the electronics. I have heard of people the welding magnetised pipe wrapping the ground lead around the pipe to offset it. I have never done this so I wouldn't know if it works. One thing for definite though when we used a amp probe and we had to measure a wire with a low current we would wrap the wire around the clamp 10 times and that would magnify the reading by ten times. So one amp would be 10 amps on the meter for more accuracy. So every time a wire is coiled it is adding another set of amps. If you had a wire wrapped 5 times and welding at 100 amps the field would equal 500 amps. Ten times would be 1000 amps. I would not like to weld around that field all day. I cringe when I see welders wrap the lead around there arm a few times. Look up inductance heaters online. The can boil copper without ever touching it. Just the electromagnetic field melts the copper. So sorry for the long rant but that it my opinion.
While a coiled lead will create a magnetic field, it will not heat up your arm if you put it through the center. If you put a magnetic, or paramagnetic material inside the field, flow will be induced in the material that is inside the coil. The magnetic flux inside the material inside the coil will have eddy currents in it which will internally heat the material. These eddy current losses can create quite alot of heat, especially at high frequencies, enough to melt the material in some cases.
While the coil may or may not have an impact on teh electronics, wrapping it around your arm won;t cause it to heat up, unless you have a metal rod in it. That said, there is likely some small amount of radiation being emitted by the wire that, over time may do something.
Inductance heaters usually also switch much faster than your welding AC waveform, which maxes out around 240Hz. If you switched it fast enough, with your arm in the middle, it WOULD cook it. That's how a microwave works. The frequency depends on the magnetic permeability of the material.
Optimal heating happens when you are basically pushing the material you are trying to heat right up the saturation point. This is why you can switch slower for larger pieces. They can handle a lot more magnetic flux before saturation. Once the material saturates, then trying to induce more flux with more current or more duration will be useless. So, you reverse the polarity and go the other way. Back and forth, back and forth. The hysteretic and eddy losses heat up the material.
This is the EXACT same principle (but essentially in reverse) that allows the same amount of current from a smaller transformer in an inverter welder. A older style transformer welder needs a huge transformer, because it's confined to switch at 60Hz. It needs a core that can handle a LOT of flux to transfer the power without saturating. However, an inverter welder switches must faster, and its core can be much smaller.
If you allow a magnetic material to saturate, it stops acting like a magnetic material. This is BAD NEWS BEARS in transformer and inductor world. A transformer looks not like a transformer, but more like a dead short. Same goes for an inductor. Now imagine saturating a transformer that was connected to 220V mains. Now you can see why they are so big.
Now, if you coil your welding leads, you form a nice little air-core inductor. The inductance will be so small that it most likely won't do anything. It will, however, broadcast all SORTS of switching noise. Since your inverter welder has a PWM switching overlay to control the current, even in DC, that switching frequency is most likely getting radiated, depending on the filtering in the machine. I don't know what the frequency is for everlast. Most likely just above 20kHz, so it doesn't drive you nuts with a high pitch whine.
A coiled lead will heat up over time, but it would take a while! My parents remodeled a house that caught on fire. The guy left one of those extension cord shop lights on while he was on vacation. He left it coiled up with the light on, and from what I understand that creates a transformer. It took about 4 days but it finally generated enough heat to catch on fire.
Hmmm? Never heard of any of this but I usually have my lead uncoiled and stretched out on the floor but this is usually for making moving around easier. If I'm sitting at the table welding I sometimes only uncoil what I need to reach the table. I always uncoil the MIG lead completely just to aid the wire moving inside the conduit .
I have read that having your torch lead coiled up can interfere with HF arc starting. Ever since I read that, I ALWAYS uncoil the torch lead completely and keep it away from my body as much as possible. Try not to put yourself in between the torch and ground cables. Not that it will kill you on the spot, just a precaution that will keep you out of the field. Can't hurt.
As a side note, If you experience problems with arc blow in stick or arc wander in TIG, the cables can be coiled around the table leg, to help solve the issue. It's rare, that you'll get arc blow, but sometimes if the tig arc is bouncing around in the root, the magnetism of the metal particularly on a knife edge can destabilize the arc and make it wander. To get the arc to stabilize, it may take a little experimentation, and searching for the right "leg" to wrap it around, but it can help out somewhat.
zoama585 I was wondering how you like the powerpro 256. I was torn between that and the powertig. Ultimately I went with the powertig because for the lift arc. I will be welding around sensitive car electronics. I know it's a million to one that it would fry a computer but I don't even want to take the chance. I work with some performance cars and the computers get programmed by laptop so the cars computers are expensive.
I like the 256, now that I won the PP60 and I-Mig250p (last contest), I only use the 256 for tig welding and it works great. If you only need tig, the 250ex has double the duty cycle at 250 amps and cost $200 less.Quote:
Originally Posted by Cippee
I'm very jealous I want the I-Mig250p. It looks like a very serous machine. I bet it can spray transfer very well.
@SeanMurphy265 I would be willing to bet that the heat generated was from the wire acting as a heating coil and not from the electromagnetic field.