What you need to know to build your own welder cord for the Lincoln PowerMig 210MP.
Note: this is by no means a complete guide to wiring a welder (or any tool). Follow these instructions at your own risk.
The Lincoln PowerMig 210 MP welder has a terrible 220V power cord. It is too short, very stiff, and if you’re a hobbyist you probably don’t want the gigantic 6-50 plug but something more suitable, so that you don’t need a bunch of adapters or an extension cord the size of a garden hose. Here’s what you need to know to make your own:
- The welder only uses 15 amps. See Lincoln’s website . Seems low, but this is also confirmed by Lincoln’s own choice of power cord. This is very important because it allows you to use smaller and cheaper plugs and more flexible cables than what you’d need for a larger welder.
- The included power cord has a NEMA 6L-20R (female) on the welder side, and a NEMA 6-50P (male) on the wall side. The 6L-20R is rated for 20 amps (that’s what the 20 means), and the 6-50P is analogously rated for 50 amps. This is sufficient since the welder only uses 15 amps. The 6-50 plug is total overkill for this welder - the reason Lincoln put this on the cord is because 6-50 is sort of a standard for welders (and makes sense for larger welders). However it is totally impractical for your typical hobbyist that does not have a 50 amp circuit anyway.
- The power cord is 6 feet long and 14AWG (American Wire Gauge). A 14AWG cable can carry 15 amps. Ampacity chart . Note: smaller gauge = thicker wire. There is no need to go thicker in your own cord.
You will need:
A L6-20R female connector for the welder side of the cord. Leviton is a good brand - they make several L6-20R female plugs. One suitable plug is the Leviton 2323 .
A male connector for the wall side of the cord. You should get something that works well your sockets / extension cords and other tools. If you’re not sure, a NEMA 6-15P or 6-20P are good non-locking choices, and a NEMA L6-20 or L6-30 are good locking choices.
Make sure that whatever you get is rated for 250V and at least 15 amps. I have had very good experiences with the Leviton black-and-white industrial plugs - they are reasonably priced and super sturdy. Specifically I can recommend the the Leviton 2621 (NEMA L6-30), the Leviton 5466-PLC (NEMA 6-20 plug, with integrated LED indicating power) and the Leviton 5466-C (same thing but without the LED).
A cable. You want a 14/3 SOOW or SJOOW cable for maximum flexibility (these are very flexible rubber cables), or a SEOOW or SJEOOW cable (slightly less flexible but also cheaper).
Cable choices on Amazon can be confusing and prices fluctuate wildly - if you want more choice, clearer specs, and more stable prices, check out McMaster .
More info about NEMA connectors
There are about a gazillion NEMA connectors for all sorts of applications. Here’s a very incomplete summary:
Most NEMA connectors are coded with something like “NEMA (optional L) (series number)-(amperage) (P or R)”, e.g. NEMA 5-20P or NEMA L6-30R.
The L indicates that this is a twist-lock connector (no L means that it just plugs in and out in a straight motion). Note that a locking connector is not compatible with the equivalent non-locking connector.
The series number indicates the NEMA series. Connectors in the same series have similar characteristics (but are not generally compatible with each other).
The amperage indicates how many amps a connector of this type can carry.
P or R indicates whether a connector is a plug (male) or receptacle (female). It is often omitted (for example, you will see references to “a 6-20 plug” instead of 6-20P.
Most NEMA male connectors are only compatible with the exact same type of female connector (and vice versa), but there are a few exceptions that are cross compatible.
For 110 V use, you only need to know about series 1 and 5. For 220 V use at home, you only need to know about series 6, L6, 10 and 14. It’s very unlikely that you’ll run into anything else for home use.
Some more on NEMA series:
- Series 1 and 5 are 110V connectors (not suitable for 220V), and have 2 and 3 prongs respectively. The smallest in the series, 1-15 is a 2 prong household connector, and a 5-15 is a 3 prong household connector. There are larger connectors in the 1 and 5 series but they’re not useful for this welder.
- Series 6 and L6 are 3-prong 220 V connectors and come in various sizes. They come in sizes from 15 up to 50 amps. The 15 and 20 amp are often use for larger amateur or small professional power tools, like table saws, dust collectors etc. The 6 does not have a lock, and the L6 has a twist lock. Note that 6 and L6 are not compatible with each other.
- Series 10 and 14 may be important to you because that’s what some dryers and electric ranges use, so if you plug into a dryer outlet you will need one of those.
What is handy to know is that the NEMA 6-20R receptacle will accept both NEMA 6-20P and NEMA 6-15P plugs. So if you install 6-20R receptacles in your shop, you can plug in two kinds of plugs.
More info about cables
Cables are rated by the number of connectors, the thickness of the connectors, the supported voltage, the type of insulation, and various other things. What you need is a cable with 3 connectors (2 for power, 1 for ground), with a connector thickness of 14AWG. This is also known as a 14/3 cable.
Further, cables are rated with a letter code (you may have seen “STJ” or “SOOW” and similar codes on cords). The letters indicate the voltage rating, the type of insulation, and various other things (it’s pretty complicated, see wikipedia ).
What you should know is this:
S = Severe service (you want this for a welder).
J = Junior (300V rated, vs 600V). Since you are only using 220V, Junior is fine.
T = Thermoplastic (i.e. not rubber), indicates a stiff cord that gets stiffer when it is cold. You don’t want this.
E = Thermoplastic but a higher grade that’s more flexible than your basic thermoplastic, but not as flexible as rubber.
Neither T nor E = rubber, this is the most flexible and also the most expensive. You know those high quality power tools with really nice supple cords that don’t get in your way? That’s what this is.
OO = Oil resistant. This is good for a welder that will likely be used in a dirty environment.
W = Weather resistant. Again good for a welder that will be likely used in a rough environment.
Therefore a SJOOW or SOOW cable is a good choice - it’s rated for Severe service, it’s rubber, and it’s oil and weather resistant.