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John C1004

220/230 extensions

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I have my table saw and jointer planer combo receptacles on my ceiling, over the tools. I was watching a Vondriska video and he had an approximately 3 ft to 4 ft cord hang down then just plugged the tools into that. Currently I use a ladder to plug each one in when needed. Was a safety measure to help with the kids running through the garage shop and not wanting the machines powered all the time. I have next to no electrical knowledge and was wondering if those extensions can be bought or if they have to be made. 

Thank you,

John

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You can buy the plugs and wiring to make your own of any length or you can buy already made cords (typically in longer lengths). Search for “generator cord”

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There are numerous different NEMA plug types for 240 volt circuits (and yes it definitely is 240:)).   The best type to use in that application would the one that twists and locks male and female together.  I suggest you make your own cord so it is only as long as you need to reach your machines.  Watch that the wire guage is adequate for the current rating of the circuit.  Plugs and receptacles must also be propperly sized for the current draw.  

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Yes, you can make your own. Run the cord out of a junction box, using the appropriate connector, and then put a female cord end on it. You need to provide some robust strain relief for the part that is suspended. For that you need a woven wire strain relief grip, known colloquially as a 'horse cock'.  That hangs from a eye hook in the ceiling. I prefer this type to the kind that connects directly to the box because the box can get wrecked in a hurry.

.94-1.25" Diameter Pass & Seymour FC94 Closed Mesh Bus Drop Duty Support Grip

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Yes you use strain reliefs to do that as shown above.They are available from Amazon and run about $20, HD sells some nice wire to use with them. I had several in my old shop.

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Use a type of wire that has the first two letters  "SO".  It most likely will be something like SOOW, but the first two letters (long story shortened) are the most important.  SJ wire will look similar, but it costs almost as much, and doesn't last as long.

Buy Hubbell ends for the wire.   On the back of the package will be a diagram that shows exactly how much to strip both the cover, and the conductors.  The SO cover is very tough.  You can carefully cut into it with a sharp utility knife, but bend the wire away from the cut, and don't quite cut it all the way through the cover.  Let the last little bit tear.  The insulation on the conductors inside the cover is not nearly as tough as the outside, and you don't want to cut into those.

If you aren't comfortable with cutting the cover with surgical precision, carefully chew around the cover with diagonal cutters.

Use the correct sized straight blade screwdriver to tighten the screws in the lugs.  They need to be Really tight, and it's hard to strip them if you have stripped the wire the right amount, and seated the wire all the way home under the lugs.

Hopefully, you remembered to slide the butt end of the connector on the wire before hooking up the conductors to the lugs, and now all that's left is to slide the hull of the connector in place, and tighten the remaining screws.

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When chosing the connectors, it is important to be sure the style is rated for at least the current draw of the machine. To get a twist-lock style, you might have to go with a size greater than minimum.

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10 hours ago, wtnhighlander said:

When chosing the connectors, it is important to be sure the style is rated for at least the current draw of the machine. To get a twist-lock style, you might have to go with a size greater than minimum.

Very important. If your machine needs 30A at 240V, then you need a 30A, 250V, 3 wire plug. There are also 250V, 3 phase, 4 wire; 125/250V 4 wire; and 125/250V 3 phase 5 wire configurations. You must use the correct configuration, not one that 'will do the job'. 

To do otherwise can create a danger to life and/or equipment if something else is plugged into that outlet.

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On 12/3/2019 at 4:12 PM, Tom King said:

The SO cover is very tough.  You can carefully cut into it with a sharp utility knife, but bend the wire away from the cut, and don't quite cut it all the way through the cover.  Let the last little bit tear.  The insulation on the conductors inside the cover is not nearly as tough as the outside, and you don't want to cut into those.

That's exactly how I do it. A shallow circumferential cut then bend the cable. If the remainder of the sheath doesn't part on its own, then careful cuts with a box cutter will finish the job without the blade ever touching the wire insulation.

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