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View moosie's profile

Sizing my TS power cord for 240V

by moosie
posted 07-27-2017 03:22 AM


26 replies so far

View MrUnix's profile

MrUnix

7452 posts in 2655 days


#1 posted 07-27-2017 03:27 AM

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

Cheers,
Brad

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

View moosie's profile

moosie

14 posts in 802 days


#2 posted 07-27-2017 03:36 AM

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?

View Loren's profile

Loren

10477 posts in 4104 days


#3 posted 07-27-2017 03:56 AM

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.

View ArtMann's profile

ArtMann

1419 posts in 1272 days


#4 posted 07-27-2017 04:32 AM

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.

View Madmark2's profile

Madmark2

476 posts in 1044 days


#5 posted 07-27-2017 05:08 AM

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

View WhyMe's profile

WhyMe

1169 posts in 2017 days


#6 posted 07-27-2017 04:11 PM



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.

View moosie's profile

moosie

14 posts in 802 days


#7 posted 07-28-2017 11:25 AM

Thanks guys. I appreciate the good information.

View jonah's profile

jonah

2075 posts in 3754 days


#8 posted 07-28-2017 11:40 AM

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.

View moosie's profile

moosie

14 posts in 802 days


#9 posted 07-28-2017 08:16 PM


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.

View jonah's profile

jonah

2075 posts in 3754 days


#10 posted 07-28-2017 09:44 PM

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.

View bigJohninvegas's profile

bigJohninvegas

652 posts in 1918 days


#11 posted 07-28-2017 10:02 PM

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

-- John

View moosie's profile

moosie

14 posts in 802 days


#12 posted 07-29-2017 12:10 AM



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

- bigJohninvegas

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.

View Holbs's profile

Holbs

2218 posts in 2485 days


#13 posted 07-29-2017 12:17 AM

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

-- The Carpenter Bee is derived from the Ancient Greek word wood-cutter "xylokopos/ξυλοκὀπος"

View MrUnix's profile

MrUnix

7452 posts in 2655 days


#14 posted 07-29-2017 12:32 AM

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

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

View moosie's profile

moosie

14 posts in 802 days


#15 posted 07-29-2017 12:39 AM



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

- MrUnix


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…”

View MrUnix's profile

MrUnix

7452 posts in 2655 days


#16 posted 07-29-2017 12:56 AM

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

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

View moosie's profile

moosie

14 posts in 802 days


#17 posted 07-29-2017 01:05 AM

That helps, thanks.

View bigJohninvegas's profile

bigJohninvegas

652 posts in 1918 days


#18 posted 07-29-2017 01:44 PM


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

- MrUnix

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…”

- moosie


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.

-- John

View jonah's profile

jonah

2075 posts in 3754 days


#19 posted 07-29-2017 03:28 PM

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.

View Redoak49's profile

Redoak49

4107 posts in 2444 days


#20 posted 07-29-2017 06:03 PM

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.

View MrUnix's profile

MrUnix

7452 posts in 2655 days


#21 posted 07-29-2017 06:12 PM

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

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

View Gilley23's profile

Gilley23

489 posts in 838 days


#22 posted 07-29-2017 07:59 PM



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.

View Steve Peterson's profile

Steve Peterson

408 posts in 3538 days


#23 posted 07-29-2017 08:30 PM

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.

-- Steve

View jonah's profile

jonah

2075 posts in 3754 days


#24 posted 07-30-2017 12:01 AM


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.

- Gilley23


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.

View MrUnix's profile

MrUnix

7452 posts in 2655 days


#25 posted 07-30-2017 12:06 AM

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

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

View moosie's profile

moosie

14 posts in 802 days


#26 posted 07-30-2017 12:43 AM



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

- MrUnix


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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