# Sizing my TS power cord for 240V



## moosie (Jun 14, 2017)

Hi folks,

First time poster here.

I am awaiting delivery of my new Grizzly G0771Z table saw. Pretty excited. Serious upgrade from the little 35 year old Makita job saw with a rusty so-called fence.

Anyway… The saw runs on either 120 or 240V, single phase, and is pre-wired for 120. I intend to run on 240V. It comes with a 6' power cord, 5-15 plug, 14 AWG. Full load is 15A on 120, and 7.5A on 240.

Obviously I'll need to replace the connector with a 6-15. At the same time, I really wish it was a 10' cord. I do not wish to starve my saw of current. Can someone help me properly size the new cord? I'm sure there's a formula addressing length, voltage, amps, etc, but I haven't been able to find one.

Once I know what I need, then I'll either buy a pre-made cord, and cut the female end off (to wire the TS switch), or order one from http://stayonline.com or similar.

Tag on question, while I'm on the topic. I also need to add a 240V circuit to the garage / shop. I don't have DC yet, but it's a matter of time. I anticipate DC and TS will be the only two machines I'll run on 240, and the DC I'm looking at pulls 9A max. With the TS, that's 16.5A. Do I need a 30A circuit, or will 20A be OK?

Thanks!


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## MrUnix (May 18, 2012)

14 gauge would be fine. Don't run multiple machines on a single 240v circuit.

Cheers,
Brad


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## moosie (Jun 14, 2017)

Thanks.

My panel only has five open slots. One will be the 20A 120 that I badly need for smaller tools. DC and TS will each consume a pair.

What if I eventually add one more 240V machine? The usual single-man caveat applies - I can only run one thing, plus DC, at a time. Is it OK to put all my tool machines on the one 240V circuit, as long as I only run one at a time, and the DC is isolated to it's own? Or is this a violation?


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## Loren (May 30, 2008)

You can install duplex breakers to increase the
capacity of your panel. With duplex breakers
you'll have 10 slots equivalent if you want to
replace all the breakers and your two 240v lines
will take a pair each. It's not that complicated 
to set it up but more than I can explain clearly
here. Duplex breakers may be controversial
among electricians. I've used them for years
with no problems.

I've always had setups where each 240v outlet
was on its own circuit so to run another machine
switching plugs was needed.


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## ArtMann (Mar 1, 2016)

Running multiple 240VAC outlets on a single circuit is not prohibited in any place I have ever done any wiring. If you are going to call in an inspector, you should check with him ahead of time to avoid problems. I have encountered some pretty strange requirements before. There is no engineering reason that I can think of to run multiple circuits to multiple machines if you aren't going to use them at the same time. Even if you do, the worst that can happen is your breaker will open up after several seconds. My shop is wired for multiple 240VAC outlets on a single circuit and in 12 years or so, I have never had a problem. I do have my air compressor and dust collector on unique circuits because you never know when the compressor will cycle and a dust collector is always used with some other machine.


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## MadMark (Jun 3, 2014)

Ummmm, don't cut the cord. Order the 240v kit.

I wired a 6-20 receptical on a 20A sub panel with 12/2 w/gnd since I was not going to split the 220 into a pair of 110's

M


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## WhyMe (Feb 15, 2014)

> Running multiple 240VAC outlets on a single circuit is not prohibited in any place I have ever done any wiring. If you are going to call in an inspector, you should check with him ahead of time to avoid problems. I have encountered some pretty strange requirements before. There is no engineering reason that I can think of to run multiple circuits to multiple machines if you aren t going to use them at the same time. Even if you do, the worst that can happen is your breaker will open up after several seconds. My shop is wired for multiple 240VAC outlets on a single circuit and in 12 years or so, I have never had a problem. I do have my air compressor and dust collector on unique circuits because you never know when the compressor will cycle and a dust collector is always used with some other machine.
> 
> - ArtMann


International Residential Building Code prohibits multiple receptacles on circuits greater than 20 amps. So multi-outlet 20A 240V is okay, 30A and up not okay.


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## moosie (Jun 14, 2017)

Thanks guys. I appreciate the good information.


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## jonah (May 15, 2009)

Cutting the plug off the end of the cord is perfectly fine. 14AWG is fine for 7.5A, but you lose nothing other than a little money by using bigger wire. It's up to you.


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## moosie (Jun 14, 2017)

> Cutting the plug off the end of the cord is perfectly fine. 14AWG is fine for 7.5A, but you lose nothing other than a little money by using bigger wire. It s up to you.
> 
> - jonah


The cord coming on the saw is only 6 foot. I'm going to need to lengthen it anyway. I hear all these warnings about running a machine like this on an extension cord, so I'm being careful.

For a 7.5 amp load, roughly how long can my cable be before I need to move up to 12 AWG? 20 feet? 50 feet?

Thanks.


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## jonah (May 15, 2009)

The wiring chart will say something like 30-50ft for 14AWG, but honestly I'd just make a 10 foot power cord with 12AWG and be done with it. Again, all you lose is a bit of cash moving to thicker wire, and you give yourself more of a safety margin if you need to go longer at some point via an extension cord.


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## bigJohninvegas (May 25, 2014)

That new Grizzly saw will come with a manual that will tell you what wire size it needs.
I have a grizzly 17" bandsaw
While it came prewired for 220. It had no plug and the cord was to short for what I needed.
The instruction manual had all the specs for what was required for both cord and plug. 
It only had about 6' of cord and I needed a cord about twice that length. Instead of an extension cord I chose to replace the short cord. Very easy. And good instructions. 
A 10 foot cord will be no problem. Even


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## moosie (Jun 14, 2017)

> That new Grizzly saw will come with a manual that will tell you what wire size it needs.
> I have a grizzly 17" bandsaw
> While it came prewired for 220. It had no plug and the cord was to short for what I needed.
> The instruction manual had all the specs for what was required for both cord and plug.
> ...


This is why I asked. I read the manual, and while it describes converting from 120 to 240, and describes proper grounding, it does not specify cord length or wire gauge, except to say what it comes with, and that one shouldn't use an extension cord, but if you're going to, then keep it below 50 ft, and at least 12 AWG.

Since the plan is to create a new direct-wired power cord, and not an extension, I wasn't sure.



> The wiring chart will say something like 30-50ft for 14AWG, but honestly I d just make a 10 foot power cord with 12AWG and be done with it. Again, all you lose is a bit of cash moving to thicker wire, and you give yourself more of a safety margin if you need to go longer at some point via an extension cord.
> 
> - jonah


I don't know where that wire chart is, but you make a good point. I like margin of safety.


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## Holbs (Nov 4, 2012)

any machine power cord I purchase (have done such for my PM66 saw and a 220v extension cord which I found out having a metal box is not a good idea, but I am just bringing up the SOOW material here) is that thick black rubber that you can run a steam roller over (SOOW material). http://lumberjocks.com/topics/129010


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## MrUnix (May 18, 2012)

IMO, you won't accomplish anything by going up to 12ga from 14ga other than spending more money, particularly on a permanent fixed cord that will only be used for that purpose. 14ga can do [email protected] easily up to 50 feet (you could actually get by with 16ga!). At 50ft, 14ga would have approx. a 1.9v drop, 12ga would be approx. 1.2v. For a 10-15 foot cord, there is virtually no difference between the two (~1/4 of a volt or so).

Cheers,
Brad


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## moosie (Jun 14, 2017)

> IMO, you won t accomplish anything by going up to 12ga from 14ga other than spending more money, particularly on a permanent fixed cord that will only be used for that purpose. 14ga can do [email protected] easily up to 50 feet (you could actually get by with 16ga!). At 50ft, 14ga would have approx. a 1.9v drop, 12ga would be approx. 1.2v. For a 10-15 foot cord, there is virtually no difference between the two (~1/4 of a volt or so).
> 
> Cheers,
> Brad
> ...


See, I don't have a table, or the knowledge to figure that out.

What you say makes me wonder why Griz basically contradicts with their extension cord mantra. In fact, I was very surprised to see that the stock power cord was only 14 gauge, because for the "shortest possible" extension they're recommending 12. That's how I got to wondering if there was some loss just because it's extension vs direct.

I wish they'd simply have said "when you convert to 240, construct your cord as follows…"


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## MrUnix (May 18, 2012)

> See, I don t have a table, or the knowledge to figure that out.


There are like a zillion on-line calculators and charts out there… like this one and this one.

As for their recommended extension cord size - that is most likely so it can do either 120/240. A 50 foot 12ga cord will only have about a 2% voltage drop at 120v - while a 14ga one would have slightly more than 3%. Typical sizing is to keep the voltage drop at the far end to less than 3%.

Cheers,
Brad


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## moosie (Jun 14, 2017)

That helps, thanks.


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## bigJohninvegas (May 25, 2014)

> IMO, you won t accomplish anything by going up to 12ga from 14ga other than spending more money, particularly on a permanent fixed cord that will only be used for that purpose. 14ga can do [email protected] easily up to 50 feet (you could actually get by with 16ga!). At 50ft, 14ga would have approx. a 1.9v drop, 12ga would be approx. 1.2v. For a 10-15 foot cord, there is virtually no difference between the two (~1/4 of a volt or so).
> 
> Cheers,
> Brad
> ...


I think I used 12g because that is what Home depot here had in stock. But my book says 14g

```
220v, and 12g
```
 120v. I have read here where some use and extension cords and replace the ends with 220v plugs. I did not like that idea, and found that home depot sells the same style wire that comes on our machines by the foot. Has what feels like a better insulation and looks right too. Its been awhile, but I paid a little over $2 per foot when I bought the 12g wire. And I bought 15'. Was worth the one time purchase for me. My band saw used about 4' inside the tool to run it from the switch all the way out. I talked to my electrician who installed the 220v circuit for me about extra length and extension cords. They are fine to do both when we are doing the short runs that we are talking about here. It would be a bad idea to run 50' cords. I was advised that if I wanted to do extension cords that I should use the twist lock plugs. 
so I did just what you are looking to do. worked out just fine. 14g if you can find it.


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## jonah (May 15, 2009)

The reason I recommended 12AWG is because if he ever wanted to plug the saw into an extension cord he'd want to make a 12AWG cord.


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## Redoak49 (Dec 15, 2012)

In the long term, the 12 gauge will be more useful for other tools. I have a couple of them to use on a couple different machines. I do not have to worry about finding the right one.


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## MrUnix (May 18, 2012)

> In the long term, the 12 gauge will be more useful for other tools. I have a couple of them to use on a couple different machines. I do not have to worry about finding the right one.
> - Redoak49


For an extension cord, it is better to go bigger. I have one 25 footer I made using 6ga wire so I can run my welder off of it 

Cheers,
Brad


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## Gilley23 (May 9, 2017)

> The reason I recommended 12AWG is because if he ever wanted to plug the saw into an extension cord he d want to make a 12AWG cord.
> 
> - jonah


Just use 12ga extension cords, don't worry about the short cord from your machine. The issue comes with the EXTENDED length of the cord, not the short cord from the machine.


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## stevepeterson (Dec 17, 2009)

I cut the cord on my tablesaw to be about 2' long and put a twist lock plug on it. This makes it easier to unplug the saw when changing blades. I use a 10' extension cord to the wall plug.


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## jonah (May 15, 2009)

> The reason I recommended 12AWG is because if he ever wanted to plug the saw into an extension cord he d want to make a 12AWG cord.
> 
> - jonah
> 
> ...


The short cord from the machine becomes a part of the extended length of the cord as soon as you plug it in. Electrically, it is motor >>> cord >>> receptacle. Cord includes the power cord as well as any extension cords. So an undersized power cord will heat up and drop voltage. Thus there is no reason not to spend another $1.50 in wire to get 12AWG wire for the power cord.


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## MrUnix (May 18, 2012)

> The short cord from the machine becomes a part of the extended length of the cord as soon as you plug it in. Electrically, it is motor >>> cord >>> receptacle. Cord includes the power cord as well as any extension cords. So an undersized power cord will heat up and drop voltage. Thus there is no reason not to spend another $1.50 in wire to get 12AWG wire for the power cord.
> - jonah


With a properly sized extension cord, there is no difference between using it and just plugging the machine into a wall outlet (which itself is nothing more than a long extension cord from the breaker box)... the smaller short cord from the machine will not heat up any more or less than it would normally.

Cheers,
Brad


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## moosie (Jun 14, 2017)

> The short cord from the machine becomes a part of the extended length of the cord as soon as you plug it in. Electrically, it is motor >>> cord >>> receptacle. Cord includes the power cord as well as any extension cords. So an undersized power cord will heat up and drop voltage. Thus there is no reason not to spend another $1.50 in wire to get 12AWG wire for the power cord.
> - jonah
> 
> With a properly sized extension cord, there is no difference between using it and just plugging the machine into a wall outlet (which itself is nothing more than a long extension cord from the breaker box)... the smaller short cord from the machine will not heat up any more or less than it would normally.
> ...


Which seems to explain why Grizzly ships the saw with a short 14 AWG, yet advises 12 AWG for any extension.


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