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Forum topic by Grant_ posted 02-06-2017 02:35 PM 2029 views 0 times favorited 24 replies Add to Favorites Watch
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Grant_

7 posts in 313 days


02-06-2017 02:35 PM

Topic tags/keywords: sawstop electrical power cord question

I know little about electrical stuff, but I’ve done some research and I’m looking for guidance from folks who are more knowledgeable than me.

I am in a newly built house (less than a year old) and I had the builder run a dedicated 220 circuit to my garage, since I knew I would use it for my workshop. My table saw is the only device I will have plugged into this circuit.

I just got my Sawstop 3HP PCS assembled, but now I have two problems. 1) The plug on the end of the power cable (3-prong) doesn’t match the wall receptacle (4-prong) installed by the builder, and 2) the power cord isn’t long enough for me to move the saw out into the middle of the shop. Anyone else dealt with a similar problem?

The Sawstop manual has instructions for installing a new power cord, and I’m confident I can do that, but I’m looking for confirmation from experts that this is an OK approach.

The saw is only supposed to draw 13 amps. I checked my panel, and the builder installed a 40 amp circuit breaker. The outlet in my garage wall is rated at 50 amps. I can buy the right plug at my local Lowes that is also rated at 50 amps.

Is it really just as simple as buying enough length (20-25 feet should do) of the appropriate gauge 3-conductor cable (as required per Sawstop), connecting one end to the saw, connecting the other end to the new plug, plugging in the saw, and I’m good to go? From my research it looks like 40 amps requires 8-gauge wire. It looks like I can buy that at my Lowes as well. I’m guessing I shouldn’t go any smaller than that, even though the saw only draws 13 amps?

Is there anything else I need to consider? I am very concerned about safety. I don’t want to melt any wires, burn out any motors, or cause any fires. I spent the $$ on the saw to reduce the chances of chopping off a finger, it would stink if I electrocuted myself while setting it up. :-(

Thanks!


24 replies so far

View EugdOT's profile

EugdOT

213 posts in 392 days


#1 posted 02-06-2017 03:08 PM

Is it a outlet or a sub panel? You might be able to convert your outlet if the gauge is thick enough to Handel a small subpanel so you can run lines off it. I had simular situation when I got my sawstop, I originally ran several lines to the garage during a house Reno and had the electrical just convert the 220 line to a 60 amp subpanel so I could add a 220 so I could maximize the higher gauge line so off the 60 app I have 3, 220 lines I could run without taxing the main panel.
All you need is a 20amp breaker for the sawstop and a new receptacle. Then use the remaining amp amount for another breaker like something like a dust collection system.
You will need this outlet either way
Just a idea?

View Grant_'s profile

Grant_

7 posts in 313 days


#2 posted 02-06-2017 03:31 PM

Thanks for the reply. To answer your question, it’s an outlet not a sub-panel. I’m told that local building codes require 4-prong outlets on 220 lines. Based on that, it sounds like I’m stuck replacing the plug on my SS.

View Fred Hargis's profile

Fred Hargis

4757 posts in 2330 days


#3 posted 02-06-2017 03:33 PM

A lot of folks run their 240V tools off dryer outlets and other receptacles that are oversized for the service. You don’t need to size your extension to the outlet, instead size it to the motor. So all you need to do is get some #12 wire (SO or whatever service duty you want) put a 20 amp receptacle (6-20R) on the saw end for the saw plug, and put a plug on the other end that will use the 2 hots and the ground (the neutral on the plug will be unused). Plug everything up and you’re good to go. Of course, there’s several dozen other ways to do this as well (including changing to a sub panel…good idea actually), but this is probably the easiest. Ask here about the wiring hook on the plug up if your unsure.

-- Our village hasn't lost it's idiot, he was elected to congress.

View clin's profile

clin

751 posts in 833 days


#4 posted 02-06-2017 06:52 PM

I simply made an extension cord for mine, just as Fred described. Build the cord to match the load (the saw). Assuming it’s a relatively short cord 20 ft, not 200 ft. Use the largest wire you can, that will fit the socket that matches the SawStop plug. Use whatever plug you need to fit your 240 V wall socket.

Also, those 4-wire sockets have two hot leads (that’s 240 V across them), a neutral, and a ground. Your saw just needs the two hots and the ground. The neutral is in the socket because some loads might use both 240 V and 120 V. You get 120 V from each hot to neutral, and 240 between the hots. While the ground is more or less at the same voltage as the neutral. The ground is never meant to carry loads. So some loads need the neutral, to power any 120 V load that the 240 V equipment might have.

Your SawStop only needs the two hots for 240 V power and the ground for safety. It doesn’t use a neutral. So you simply don’t wire up the neutral on the wall end of your extension cord. Also, just get a cable with three total wires (2 hots and a ground).

-- Clin

View brtech's profile

brtech

1005 posts in 2759 days


#5 posted 02-06-2017 09:01 PM

Yes, build a new cord. Get a plug to match your outlet. As above, size the wire to the load, but be generous: round down (AWG smaller number is bigger). If 12# is maybe close, then go 10#. 8# is overkill.

It’s pretty easy to do, and there isn’t much chance of electrocution. Wire it up, check with a multimeter that what you think is 220 is really 220, and turn it on.

The only safety issue was covered above: you want the ground (typically green wire, but don’t depend on color), not the neutral. They are tied together at the panel, but you want the ground anyway.

View sawdustdad's profile

sawdustdad

334 posts in 722 days


#6 posted 02-06-2017 09:54 PM

Go ahead and make up the adapter cord, but a better solution is to put a subpanel where your 50A outlet is. Then come out of that with several circuits for various loads. Looks like you’d need an extension cord for your saw regardless.

-- Murphy's Carpentry Corollary #3: Half of all boards cut to a specific length will be too short.

View WhyMe's profile

WhyMe

910 posts in 1397 days


#7 posted 02-07-2017 02:23 AM



Thanks for the reply. To answer your question, it s an outlet not a sub-panel. I m told that local building codes require 4-prong outlets on 220 lines. Based on that, it sounds like I m stuck replacing the plug on my SS.

- Grant_

4 prong outlets are only required on range and dryer circuits. They should not be required on all 240V circuits. That is senseless.

View MrUnix's profile

MrUnix

5997 posts in 2035 days


#8 posted 02-07-2017 02:48 AM

Is it really just as simple as buying enough length (20-25 feet should do) of the appropriate gauge 3-conductor cable (as required per Sawstop), connecting one end to the saw, connecting the other end to the new plug, plugging in the saw, and I’m good to go?

Yes.

Don’t make it harder than it needs to be. Get a 25’ foot roll of 10/3 (or 12/3) SOOW/SJOOW cable and the proper plug from the BORG and start making sawdust.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View rwe2156's profile

rwe2156

2714 posts in 1317 days


#9 posted 02-07-2017 02:46 PM

If you told him what you were going to do, he installed the wrong kind of outlet. Its on a 30-50A circuit depending on the wire size.

My suggestion is to change that outlet to a small sub panel. You will get a 240V circuit and 2 or 3 120V circuits depending on the panel.

This will be important when you find a need for a dedicated circuit for a compressor or dust collector.

-- Everything is a prototype thats why its one of a kind!!

View pintodeluxe's profile

pintodeluxe

5466 posts in 2650 days


#10 posted 02-07-2017 04:48 PM

I’m not sure about the code in your area, but I would never breaker a 13 amp tool at 50 amps.
I run my 3 hp PCS on a 20 amp breaker. I had the electrician run 10 gauge wire, in case it ever needed to be scaled up to a 30 amp (larger future dust collector?), but as far as the saw is concerned 20 amps is all it will ever see.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Carloz's profile

Carloz

973 posts in 428 days


#11 posted 02-07-2017 04:59 PM


I m not sure about the code in your area, but I would never breaker a 13 amp tool at 50 amps.
I run my 3 hp PCS on a 20 amp breaker. I had the electrician run 10 gauge wire, in case it ever needed to be scaled up to a 30 amp (larger future dust collector?), but as far as the saw is concerned 20 amps is all it will ever see.

- pintodeluxe


Come on ! You do not need a 0.05A breaker to power your cell phone !
The breaker and the circuit must be greater than the load that is the only condition and no code can tell you otherwise.
Most saws and Sawstop for sure have an internal breaker that protect the saw. The one in the panel is there to protect the circuit not the tool.

View TheFridge's profile

TheFridge

8301 posts in 1323 days


#12 posted 02-07-2017 05:32 PM

Don’t know your setup.

I’d change the breaker to a 2 pole 30A

And the receptacle to a nema 6-30R (30A 250V straight blade). And if it needs a cord end a nema 6-30P.

If the receptacle says 125/250V, has 4 terminals, or has angle blades it the wrong one.

If you need to make an extension cord get a 6-30C and 6-30P (C is female, P is male, R is receptacle)

You could probably turn that feeder into a sub panel if you wanted but I wouldn’t put anything in it that would possibly run at the same time as the saw.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View Fred Hargis's profile

Fred Hargis

4757 posts in 2330 days


#13 posted 02-07-2017 05:33 PM

There’s no code problems with doing that (running the saw on a 50 amp outlet) unless there are some really, really strange ones that are locally enacted.

-- Our village hasn't lost it's idiot, he was elected to congress.

View runswithscissors's profile

runswithscissors

2562 posts in 1862 days


#14 posted 02-08-2017 08:19 AM

Check the wire size on the SawStop. There’s a chance its only 14 gauge. A lot of tools drawing 240v at less than 15 amps only use 14 gauge. But 12 gauge is fine too. Anything heavier is just a waste of money.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

View TarHeelz's profile

TarHeelz

58 posts in 1918 days


#15 posted 02-08-2017 01:03 PM

Easier for me than building a new cord would be to swap out the 50 amp 220 breaker with a 20 amp 220 breaker and then swap out the 50 amp 220 receptacle with a 20 amp 220 receptacle.

You’ll know that you have the wire in the wall necessary for a heavier load if/when it’s ever needed.

Tools needed: Screwdriver.

-- Tar Heelz, Durham, NC USA

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