When any SA200 or SA 250 welder comes into our shop, it has auxiliary power (it will run a grinder), and the customers tell me, "ran great yesterday, but this morning, no weld. Or it was welding fine, and it died in the middle of a weld. Typically, it is one of two problems.
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CHECK YOUR RHEOSTAT
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`1. A defective rheostat, also known as the "heat" control. Do a visual check; look for broken wires,
broken white porcelain, and the wiper moves freely.
2. Check the resistance with an ohmmeter, lift the wiper arm, and lift it with a piece of paper or
a wooden shim, as shown in the far right image. The two outside terminals should read 64 ohms
+/- 10%.
3. Remove the shim and test the resistance between the wiper tab (in the center) and either tab on
the side. It should read 0 to 64 ohms smoothly, with no breaks, up and down.
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CHECK YOUR WELDER MAIN SHUNT COILS
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OPINION: The following is the author's opinion, and I assume responsibility for the content.
In my humble opinion, Lincoln Electric's engineering is unsurpassed, but as far as quality,
they could teach the Chinese how to manufacture cheaply. Case in point: the shunt coils are SA
machines. The problem is not aluminum vs. copper windings, and either alloy will suffice if
designed correctly.
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MORE INFORMATION
Replacing your shunt coils is a major job, a pain in the ass; you only want to do it once.
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1. Have a reputable shop for the job. Make sure you get a warranty, in writing, and pay for it with a credit card. It gives you leverage in a dispute.
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2. Remove the stator housing yourself, take it to a motor shop that can R &*R the shunt coils. You need the experience of servicing your machine. Check around, nobody seems to know anything today. I call it the "Age of Incompetence". I recommend to all my customers to get as comfortable with your machine as you are with your wife, girlfriend, or favorite goat!
Suppose you do not have a motor shop close. Pull the stator housing, bolt it onto a pallet, and ship it to us. We will evaluate the item, repair any necessary issues, clean and dry it out, and coat it with epoxy if we install Weldmart coils. This installation comes with a lifetime guarantee against defects in materials and installation. We have been installing and selling our coils for over thirty years, with no known failures.
Please call or email us for more details