Checking welding current

I'm picking up the radiator for the SA 200 Monday, and will be painting and
reassembling according to the wind speed over the next couple of weeks.
When I get the old gal running, I'd like to do a check on the output through
the leads.
Would I do this with a helper and an amp clamp? Set it up to weld, and then
weld with a helper watching an amp clamp on the lead? Is there another type
of tester I should use just on the main lugs off the machine? I'm just
trying to see if the output is good, and is within the range of the controls
indicate. I will be using 50' leads of #1 cable on each leg. I will be
using 7018 1/8" rod in the flat position, and making a dime size pool, and
trying to burn thirty seconds per setting. Stinger positive.
Does this sound like a plausible idea? Other suggestions, caveats, tips,
procedures or whatever appreciated.
Thanks.
Steve
Reply to
SteveB
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You need a clamp-on DC ammeter, else sure, have someone read the current.
Grant
Reply to
Grant Erwin
Unless you have a DC amp clamp..you cant do it. Most ammeters using inductince to read current, are AC only. Your machine is DC only.
Put a volt meter across the leads, see what it says. Have your helper read it while welding.
Frankly..I consider the dials on most welders to be only a a way to figure out what the needle was pointing at the last time it worked good. Then I use a grease pencil to make a mark for the size/type of rod it worked well at.
Now there is "shunt ammeters" but I dont have a clue how to hook one up for your rig.
Just wire wheel some of your scrap, grab a mixture of rod, and burn it. Set it at what the dial says..then adjust up or down as needed for each rod.
Gunner
Reply to
Gunner
My Fluke does DC amps. Has a "Max" mode too, where it remembers the max current - you wouldn't need a helper to read the meter while you're welding.
Bob
Reply to
Bob Engelhardt
You could use an automotive starting/charging current meter, which is a simple DC magnetic meter with grooves on the back for the wire. They aren't very accurate but you just place it on the lead. The one I have reads charging current to 75A with 5A graduations, or 400A starting current to 25A.
6013 or 7014 rod (and maybe 7018, haven't tried it) will weld by itself if laid flat on the work, then you could let go and read the meter.
I'd be more concerned with maximum AC line current.
Jim Wilkins
Reply to
Jim Wilkins
I found a rather nice hall effect AC/DC clamp probe by TPI at FRy's for about $60 (plug into any DMM), and it's rated for 1,600A AC / 2,000A DC. A whole lot cheaper than the Fluke equivalent and seems to work just fine.
Reply to
Pete C.
You could use a shunt type meter. The most common meter standard for these are 50 millivolts. You will need a meter movement and a shunt covering the maximum current you will be reading. The shunt should be placed in series with either welder lead observing the polarity from the welder, shunt and meter movement. This will be the most accurate, but a clamp on attachment to a DVM, as others have suggested, should be quite adequate.
Chuck P.
Reply to
Pilgrim
I would use a DC shunt, as you said, and a regular multimeter set at the lowest voltage scale (2000 mV in my case).
These shunts are not very expensive.
If you know the gauge and exact length of your cables, you can short your welder through those cables and measure voltage drop, and arrive at a fairly good current number based on resistance of cable of your gauge.
i
Reply to
Ignoramus10476
You could use an automotive starting/charging current meter, which is a simple DC magnetic meter with grooves on the back for the wire. They aren't very accurate but you just place it on the lead. The one I have reads charging current to 75A with 5A graduations, or 400A starting current to 25A.
6013 or 7014 rod (and maybe 7018, haven't tried it) will weld by itself if laid flat on the work, then you could let go and read the meter.
I'd be more concerned with maximum AC line current.
Jim Wilkins
This machine is DC only.
Steve
Reply to
SteveB
This is really good advise. I would get an analog voltmeter and measure the voltage drop just across the work lead. Measure the length, look up the resistance of that size cable and calculate the current. Note the temp of the cable and correct for that for more accuracy.
Easy, cheap, and accurate.
Reply to
Tom M
Really? Fry's Electronics Big box store to the nerds?
Ill check there myself. Id like to have one. Gunner
Reply to
Gunner
^^^^^^^
So is car starter current.
If it welds OK with the largest appropriate rod, it's working properly.
Jim Wilkins
Reply to
Jim Wilkins
That's a good idea. Voltage drop may be about 1 v olt, easily measurable with good accuracy. There are ohms per foot tables for various gauges. Attaching one
i
AWG Wire Table for BARE COPPER Wire Compiled by a program written by Fr. Tom McGahee
Compiled by Fr. Tom McGahee tom snipped-for-privacy@sigmais.com Permission granted to copy freely so long as credit line above is included
AWG = American Wire Gauge size Dia-mils = Diameter in mils (1 mil = .001 inch) TPI = Turns Per Inch (Ignoring thickness of unknown insulation) Dia-mm = Diameter in millimeters (For comparison with non-USA coilers) Circ-mils = Circular Mils. (circular mils = diameter in mils squared) Ohms/Kft = Ohms Per 1,000 Feet Ft/Ohm = Feet Per Ohm Ft/Lb = Feet Per Pound Ohms/Lb = Ohms Per Pound Lb/Kft = Pounds Per 1,000 Feet NormAmps = Normal Average Amp Capacity based on 500 circular mils per Amp MaxAmps = Maximum recommended Average Amp Capacity in Open Air based on 438.489 circular mils per Amp
Actual Amp capacity of a wire depends on form factor and method of cooling! MaxAmps assumes free flow of air around wire. Do NOT exceed this maximum without cooling! Wire wrapped in a coil or without any form of cooling may over-heat at MaxAmps! Many factors govern the ACTUAL Max Amps you can pass through a wire continuously. Be careful!
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
0000 459.99 2.1740 11.684 211592 0.0490 20402 1.5613 0.0001 640.48 423.18 482.55 000 409.63 2.4412 10.405 167800 0.0618 16180 1.9688 0.0001 507.93 335.60 382.68 00 364.79 2.7413 9.2657 133072 0.0779 12831 2.4826 0.0002 402.80 266.14 303.48
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
0 324.85 3.0783 8.2513 105531 0.0983 10175 3.1305 0.0003 319.44 211.06 240.67 1 289.29 3.4567 7.3480 83690 0.1239 8069.5 3.9475 0.0005 253.33 167.38 190.86 2 257.62 3.8817 6.5436 66369 0.1563 6399.4 4.9777 0.0008 200.90 132.74 151.36 3 229.42 4.3588 5.8272 52633 0.1970 5075.0 6.2767 0.0012 159.32 105.27 120.03 4 204.30 4.8947 5.1893 41740 0.2485 4024.7 7.9148 0.0020 126.35 83.480 95.190 5 181.94 5.4964 4.6212 33101 0.3133 3191.7 9.9804 0.0031 100.20 66.203 75.489 6 162.02 6.1721 4.1153 26251 0.3951 2531.1 12.585 0.0050 79.460 52.501 59.866 7 144.28 6.9308 3.6648 20818 0.4982 2007.3 15.869 0.0079 63.014 41.635 47.476 8 128.49 7.7828 3.2636 16509 0.6282 1591.8 20.011 0.0126 49.973 33.018 37.650 9 114.42 8.7396 2.9063 13092 0.7921 1262.4 25.233 0.0200 39.630 26.185 29.858
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
10 101.90 9.8140 2.5881 10383 0.9989 1001.1 31.819 0.0318 31.428 20.765 23.678 11 90.741 11.020 2.3048 8233.9 1.2596 793.93 40.122 0.0505 24.924 16.468 18.778 12 80.807 12.375 2.0525 6529.8 1.5883 629.61 50.593 0.0804 19.765 13.060 14.892 13 71.961 13.896 1.8278 5178.3 2.0028 499.31 63.797 0.1278 15.675 10.357 11.810 14 64.083 15.605 1.6277 4106.6 2.5255 395.97 80.447 0.2031 12.431 8.2132 9.3654 15 57.067 17.523 1.4495 3256.7 3.1845 314.02 101.44 0.3230 9.8579 6.5134 7.4271 16 50.820 19.677 1.2908 2582.7 4.0156 249.03 127.91 0.5136 7.8177 5.1654 5.8900 17 45.257 22.096 1.1495 2048.2 5.0636 197.49 161.30 0.8167 6.1997 4.0963 4.6709 18 40.302 24.813 1.0237 1624.3 6.3851 156.62 203.39 1.2986 4.9166 3.2485 3.7042 19 35.890 27.863 0.9116 1288.1 8.0514 124.20 256.47 2.0648 3.8991 2.5762 2.9376
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
20 31.961 31.288 0.8118 1021.5 10.153 98.496 323.41 3.2832 3.0921 2.0430 2.3296 21 28.462 35.134 0.7229 810.10 12.802 78.111 407.81 5.2205 2.4521 1.6202 1.8475 22 25.346 39.453 0.6438 642.44 16.143 61.945 514.23 8.3009 1.9446 1.2849 1.4651 23 22.572 44.304 0.5733 509.48 20.356 49.125 648.44 13.199 1.5422 1.0190 1.1619 24 20.101 49.750 0.5106 404.03 25.669 38.958 817.66 20.987 1.2230 0.8081 0.9214 25 17.900 55.866 0.4547 320.41 32.368 30.895 1031.1 33.371 0.9699 0.6408 0.7307 26 15.940 62.733 0.4049 254.10 40.815 24.501 1300.1 53.061 0.7692 0.5082 0.5795 27 14.195 70.445 0.3606 201.51 51.467 19.430 1639.4 84.371 0.6100 0.4030 0.4596 28 12.641 79.105 0.3211 159.80 64.898 15.409 2067.3 134.15 0.4837 0.3196 0.3644 29 11.257 88.830 0.2859 126.73 81.835 12.220 2606.8 213.31 0.3836 0.2535 0.2890
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
30 10.025 99.750 0.2546 100.50 103.19 9.6906 3287.1 339.18 0.3042 0.2010 0.2292 31 8.9276 112.01 0.2268 79.702 130.12 7.6850 4145.0 539.32 0.2413 0.1594 0.1818 32 7.9503 125.78 0.2019 63.207 164.08 6.0945 5226.7 857.55 0.1913 0.1264 0.1441 33 7.0799 141.24 0.1798 50.125 206.90 4.8332 6590.8 1363.6 0.1517 0.1003 0.1143 34 6.3048 158.61 0.1601 39.751 260.90 3.8329 8310.8 2168.1 0.1203 0.0795 0.0907 35 5.6146 178.11 0.1426 31.524 328.99 3.0396 10480 3447.5 0.0954 0.0630 0.0719 36 5.0000 200.00 0.1270 25.000 414.85 2.4105 13215 5481.7 0.0757 0.0500 0.0570 37 4.4526 224.59 0.1131 19.826 523.11 1.9116 16663 8716.2 0.0600 0.0397 0.0452 38 3.9652 252.20 0.1007 15.723 659.63 1.5160 21012 13859 0.0476 0.0314 0.0359 39 3.5311 283.20 0.0897 12.469 831.78 1.2022 26496 22037 0.0377 0.0249 0.0284
AWG Dia-mils TPI Dia-mm Circ-mils Ohms/Kft Ft/Ohm Ft/Lb Ohms/Lb Lb/Kft NormAmps MaxAmps
40 3.1445 318.01 0.0799 9.8880 1048.9 0.9534 33410 35040 0.0299 0.0198 0.0226
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Main Thread
Reply to
Ignoramus10476
Yep. Bright yellow case unit. They have a couple models that look superficially the same, two are AC only and the third is AC/DC and has the extra DC zero knob on it. It also apparently was rated something like 800A, but subsequently upgraded with stickers on the package to the 1,600A AC / 2,000A DC rating.
Reply to
Pete C.
I have an Extech Ammeter that reads AC and DC amps. It cost me $85 at Fry's Electronics.
It works great, and is fairly compact.
Reply to
Ernie Leimkuhler
Cheap, for sure. Not as easy as an ammeter. Not very much accurate, I'd say. You have unknown accuracy in the wire guage, unknown resistance in the cable connections and in the clamps. Analog meters are hard to read precisely and are only accurate to a couple of percent.
Bob
And don't start with "The OP doesn't need more accuracy than that". I'm responding to the statement that it would be "accurate".
Reply to
Bob Engelhardt
And a couple of percent isn't accurate enough for a stick welder?
How about the digital clamp on ammeter working with the high RF environment of an arc?
Who said the measurement would be made beyond the connectors? You?
Four place resistance figures for the cable aren't accurate enough? Its easy to see an analog meter and integrate out all the variations with an unstable DC arc. Seems you have never tried to measure the current of a DC welder.
Stop picking nits.
Tom
Reply to
Tom M
Jeez, calm down.
Reply to
Bob Engelhardt
Why do you want a nerd? Cats are a lot easier to take care of. ;-)
Reply to
Michael A. Terrell
Sorry. forgot the :)
Reply to
Tom M

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