Extension cord

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TXTurner

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Question - I was just reading some old posts (trying to learn everything, as I'm very new at this) and I saw a discussion where people were indicating they avoid using extension cords to run the lathe.

Is there a problem in running equipment off extensions? In my garage, I have no choice but to do this.

Mark
 
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rherrell

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If your lathe has a 120v motor a #12 AWG cord no longer than 50' won't be a problem. You CAN run a 220v motor with a cord but they're EXPENSIVE. Just be sure the wire in the cord is at least #12 and you should be fine. Just a note....the bigger the wire, the smaller the AWG #.
 
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monkeynutz

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Voltage drops can mess up your machinery or create a fire hazard. If you must use an extension, get a fat one (like used for window A/C units) and no more length than is necessary. Then, put it out of the way, so you won't trip on it while turning (or anything else), but don't run it behind curtains or other flammable material.
 

Hello

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there can be a problem
I'd recommend finding a little tutorial on how electricity works somewhere....it'll be helpful for you if you're a home owner

here's a really quick breakdown of one reason it can be a problem

electricity doesn't "flow" through the line like water moving througgh a hose. it isn't pushed through the line like water through a hose either...its drawn through the line by the circuit thats created when you turn a device on. just like with water through a line, electricity can encounter hurtles to overcome (in the world of electicity, this is known as resistence). with an extension cord, the "resistence" is the distance the electicity has to go before reaching the device that uses it to create work. long story short, the resitence there is, the more heat there is - the main problem can actually be at the outlet.
 

TXTurner

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Thanks, everyone. This is excellent advice and input.

I appreciate the help.

Mark
 

rherrell

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You WON'T get a voltage drop with a 50' #12, uhh "FAT ONE", extension cord. There's no difference if the wire is in the wall or in an extension cord. Wire is wire. The Romex used to wire houses is just glorified extension cord.
 

jeff

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Originally posted by Hello

electricity doesn't "flow" through the line like water moving througgh a hose. it isn't pushed through the line like water through a hose either...its drawn through the line by the circuit thats created when you turn a device on. just like with water through a line, electricity can encounter hurtles to overcome (in the world of electicity, this is known as resistence). with an extension cord, the "resistence" is the distance the electicity has to go before reaching the device that uses it to create work. long story short, the resitence there is, the more heat there is - the main problem can actually be at the outlet.
Not to be pedantic, but in fact, yes it does ;)

The hydraulic analogy is widely used to describe current flow.
 
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monkeynutz

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Originally posted by rherrell

You WON'T get a voltage drop with a 50' #12, uhh "FAT ONE", extension cord.
Didn't say you would... Simple fact is that the larger and shorter the extension, the better, regardless of other variables. Always better to err to the side of caution.
 
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monkeynutz

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Originally posted by wdcav1952

Jeff, I'm confused. Should I use a hose instead of an extension cord? Decisions, Decisions!! :D;);)
You won't believe this, but LOML used to think that you could not get power through an extension cord that had a knot in it... I swear... (I guess I just like 'em dumb...)
 

Rifleman1776

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Originally posted by rherrell

You WON'T get a voltage drop with a 50' #12, uhh "FAT ONE", extension cord. There's no difference if the wire is in the wall or in an extension cord. Wire is wire. The Romex used to wire houses is just glorified extension cord.

Good explanations, Rick. Just the advice he needs. I'm a proponent of nothing smaller than #12 in the shop.
 

toolcrazy

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Don't use just a straight extension cord. Use a power strip that is rated for at least the amperage of your lathe, preferably more. Reasoning is power strips have a built in circuit breaker. And never use something that is longer than 6 feet. If you must have something longer, unplug it when you’re done. Longer, non-circuit protected cords can be a fire hazard when they are plugged in for an extended amount of time. Ask any fire marshal.
 

Stephen

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Don't use an extension cord that is a reel type coiled up in a housing. If some of the wires remain in the reel and are of considerable length they get hot and burn. Happened to me once.
 

MichaelS

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Jeff is in fact correct. Extensions cord wire is stranded and coiled or if you prefer twisted around itself not solid as is romex. As a result more resistance = a amperage drop from the male to the female end. The shorter the cord the less amperage drop. Running electric motors attached to a power cord will eventually lower the efficiency of the motor. The compactor is affected as well because it takes a power surge to start the motor and if the amperage is not present at the point of connection in the motor it has to work harder to bring the motor up to its operating RPM level. If the motor operates at a lower RPM level than it was designed for it will eventually affect its performance and burn out. The heaver the cord the more amps that can be drawn through it. But the best advice you could take is to have a circuit run to the lathe as soon as funds are available and use the extension cords as they were designed, occasional use.
 

MichaelS

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Oh by the way HELLO is also incorrect when they say that amperage is not pushed through the wire. It is in fact pushed, as atoms in the conductor strike one another pushing the power through the conductor. As the device is using the amperage the atoms strike one another at a faster rate and if the conductor is underrated for the draw the device demands the conductor bleeds if you will amperage through the insulation wall which as it does is converted into heat and guess what, you have discovered FIRE. But I could be wrong! Call me el. code certified.
 

wkuhn

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Originally posted by MichaelS

Jeff is in fact correct. Extensions cord wire is stranded and coiled or if you prefer twisted around itself not solid as is romex. As a result more resistance = a amperage drop from the male to the female end. The shorter the cord the less amperage drop. Running electric motors attached to a power cord will eventually lower the efficiency of the motor. The compactor is affected as well because it takes a power surge to start the motor and if the amperage is not present at the point of connection in the motor it has to work harder to bring the motor up to its operating RPM level. If the motor operates at a lower RPM level than it was designed for it will eventually affect its performance and burn out. The heaver the cord the more amps that can be drawn through it. But the best advice you could take is to have a circuit run to the lathe as soon as funds are available and use the extension cords as they were designed, occasional use.
 

holmqer

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How you describe the analogy is less important than how you calculate voltage drop. The nominal resistance of various gauges of copper wire per foot is

12 : 0.00187 ohms / ft
14 : 0.00297 ohms / ft
16 : 0.00473 ohms / ft

So if you have a 3/4 HP lathe running on 110V...

1 HP is 735W
Typical efficiency of an inductive motor is 80%
So 0.75HP * 735W/HP / 0.8 = 689W

689W / 110V = 6.26A

Assuming 25ft of wire, the voltage drop for the 3 gauges listed above are...
12 : 0.00187 Ohm/Ft * 25 Ft * 6.26A = 0.29V
14 : 0.00297 Ohm/Ft * 25 Ft * 6.26A = 0.47V
16 : 0.00473 Ohm/Ft * 25 Ft * 6.26A = 0.74V

The heat dissipated by the wire is
12 : 6.26A * 0.29V = 1.8W
14 : 6.26A * 0.47V = 2.9W
16 : 6.26A * 0.74V = 4.6W

So unless you have a really beefy lathe, or are running really long wires you will get little voltage drop or heat dissipation in the wires.

For an example at work,
I needed to provide 8V at 3A to some equipment located next to an aircraft engine during some testing. The routing of cables from the engine to the control room took 150' of wire. I had a 8V power supply with a max permissable voltage loss of 0.25V and was using 20 gauge wire (0.0119 ohms / ft).

For this system my voltage drop was 5.36V oops! To get down to a 0.25V drop, I needed to run 150' of 6 gauge wire! Based on this information, it made more sense to put a power supply next to the engine.
 

wkuhn

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I usually don't jump into these discussions, I am not an electrician, however do know some basic electrical.
The problem with extension cord that are too small is the VOLTAGE drop,
When volts go down , amps go up creating heat in a cord that is too small. If the amps are too high for the motor it too can overheat.

To TXTurner if your ext cord feels warm, shorten it or get a new 14ga. cord assuming your lathe's motor is 120v. A typical electrical outlet is 15 amps with # 14ga wire. Some newer garages have 20 amp circuits. Check the breaker and use an appropriate ext cord. Length and gauge.

If I am wrong, please correct me.

Respectfully submitted,
Wayne Kuhn
 

wkuhn

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Originally posted by loglugger

I feel safer with 12ga.
Bob

As do I when I am running a circuit in the house or shop with romex.
However 12 ga extension cords are heavy, unweildly and expensive.
I usually buy 14 ga extension cord with some additional plugs and cut to length.
I have never had a problem when running my generator with cords streched through out the house, and believe me , I check them often.
 

hehndc

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My two cents worth, I'm with Russiawolf, make your own extension with 12 ga romex (though as Wkuhn states 12 ga is harder to work with) and be done with it.

Steve
 

W3DRM

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There have been a lot of ideas put forth in this thread. However, I'm afraid some of them are not accurate nor are they safe relative to human safety nor are they in compliance with national electrical codes.

ROMEX is NOT designed to be used as an extension cord regardless of its length or wiring size. ROMEX consists of solid wires and the insulating covering is not designed to withstand repeated stepping on or equipment moving over top of it. It is made to be placed inside of walls and for connecting wiring fixtures to/from the electrical distribution boxes. Solid wiring cannot withstand the constant flexing that is experienced with extension cords. It will fail over time and break due to the flexing. Standard extension cords use stranded wiring that is much more resistant to flexing. Also, the covering on extension cords is designed to withstand more abuse than ROMEX.

While it may be true that a mini-lathe does not draw much power I would still suggest using nothing smaller than #12 wiring for any power tool in your shop. Power distribution is based on the premise that any tool will work most efficiently when it is provided with its designed voltage and current. All wiring, regardless of size will exhibit a voltage loss due to its inherent electrical resistance. So, the larger the wiring and the shorter the length of the wire is, the smaller the loss. Loss always results in heat being generated. If you can feel any heat in the wiring or connectors, it would be wise to investigate to see if you have loose connections or are using extension cords that are too small for the tool you are using.

That's my .02 cents, based on 45+ years of experience and knowledge of power distribution and electrical circuits.
 

Hello

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Originally posted by jeff

Originally posted by Hello

electricity doesn't "flow" through the line like water moving througgh a hose. it isn't pushed through the line like water through a hose either...its drawn through the line by the circuit thats created when you turn a device on. just like with water through a line, electricity can encounter hurtles to overcome (in the world of electicity, this is known as resistence). with an extension cord, the "resistence" is the distance the electicity has to go before reaching the device that uses it to create work. long story short, the resitence there is, the more heat there is - the main problem can actually be at the outlet.
Not to be pedantic, but in fact, yes it does ;)

The hydraulic analogy is widely used to describe current flow.
if it "flowed", it'd be all over the floor
 
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Mudder

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[}:)] Y'all don't know your Ohms law from your Watts law! [}:)]

What if I have a 10 ga extension cord but the wire in the wall is 12 ga, Can I draw more amps?

My buddy lives a mile from the substation and I live six miles form the substation does he get more power than me?

The wires that run from the pole outside to my house are twisted wires, am I not on a big old extension cord?

If old Doc Brown (No relation to Jeff or Ed) was able to generate 1.37 Jigawatts instead of 1.21 that he needed could he have sent the DeLorean back through time buy going 85 miles per hour instead of 88?



Now for the serious question......

My Lathe (Nova DVR 3000) is on a 20 amp circuit run with 12 gage line. Since I cannot get right up to the outlet I have a 10 ft extension cord made from 12 gage wire. Do I have anything that I need to worry about?
 

Hello

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Originally posted by Mudder

[}:)] Y'all don't know your Ohms law from your Watts law! [}:)]

What if I have a 10 ga extension cord but the wire in the wall is 12 ga, Can I draw more amps?

that was the point I was trying to make earlier....the circuit draws the juice - it doesn't "flow"

My buddy lives a mile from the substation and I live six miles form the substation does he get more power than me?
in a p=v*i sort of way, sure....but its more like this - you two get the same amount of power (same voltage) but it takes more for the 6mile away person to get it, higher amperage


The wires that run from the pole outside to my house are twisted wires, am I not on a big old extension cord?

If old Doc Brown (No relation to Jeff or Ed) was able to generate 1.37 Jigawatts instead of 1.21 that he needed could he have sent the DeLorean back through time buy going 85 miles per hour instead of 88?

Now for the serious question......

My Lathe (Nova DVR 3000) is on a 20 amp circuit run with 12 gage line. Since I cannot get right up to the outlet I have a 10 ft extension cord made from 12 gage wire. Do I have anything that I need to worry about?
 

rwayne

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I have a table saw that runs on 220. The cord on it was not long enough to reach the wall when I had the saw in the middle of the floor. I had work done a couple different times by a couple electricans who worked for a local company here. I asked them about the problem and they said they could construct a 220 cord for me with the proper plug . They made a heavy duty extension cord for me for about $1 a foot of length.
You might try this way if you have the connections. ( I'm very leary of electricity as it can be down right dangerous if not done right.)
 

Rifleman1776

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Originally posted by rwayne

I have a table saw that runs on 220. The cord on it was not long enough to reach the wall when I had the saw in the middle of the floor. I had work done a couple different times by a couple electricans who worked for a local company here. I asked them about the problem and they said they could construct a 220 cord for me with the proper plug . They made a heavy duty extension cord for me for about $1 a foot of length.
You might try this way if you have the connections. ( I'm very leary of electricity as it can be down right dangerous if not done right.)

You overpaid. I are pretty electriks iggerent. But, even I can screw the ends onto a piece of electrical cord. Fifty cents a foot would have been fair.
 

jttheclockman

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It is amazing how many electricians show up on a question like this. Let me add to some of the reporting which some is true and some is false. The main question was can you run an extension chord for your lathe the answer is absolutly, to a limit. You need to keep the length to the shortest amount and also use the largest chord you can get which for most homeowners will be a #12. What you do is take out the voltage drop factor to a lesser degree with the increase in size of conductor and shorter length. Of course like all chords keep them out of foot traffic or in a shop away from falling objects. Very important for obvious reasons. To touch on some other points someone asked a question with tounge in cheek about being closer to a substation and getting more power and the answer truely is yes just because of voltage drop. If you live on a steet where the transformer for that part of the grid is on one end and the person on the other end of the street will lose voltage but of course not as much as one would notice. There are so many factors when it comes to electricity. In the summer the voltage at that receptacle will not be the same as it is in the winter due to power loss of airconditioner and the power companies are forever correcting power factors with changing conditions. If you have a digital voltmeter check the voltage of one particular outlet in your house various times of the day and various times of the year and you will see for yourself it does change. But todays equipment have built in safety features such as thermal switches, voltage regulators, fuses and so forth. This could go on and on and is getting off the path so use the chord but use it wisely and also use good quality outlets. Any shop should have no less than #12 wire and 20 amp circuits in it. By the way never use RX or BX as an extension chord for the reasons that were mentioned. Also Has anyone seen the price of copper these days??? Around by me it is over $3.10 /lb. This is why theft is becoming a huge problem.
 
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Mudder

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Just for giggles I called the power company and asked what the standard line voltage is and I was told it is 120 volts +/- 5% (114-126 volts)@ 60 hertz.

This was quoted to me as the standard for my area (Connecticut), your area may differ. Seeing that there can be a fluctuation of 12 volts at the wall I'm beginning to doubt that my 10 foot extension cord will do any harm.


Unless I trip over it [8D] There Lou, feel better now :D
 

edman2

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Well, here is my problem. My shop is in my garage. Limited outlets. I have a long (longer than 30 ft) extension 12/3 cord with a triple outlet on the business end run the length of the garage. Lately when I start my miter saw it kicks the circuit off. Breakers are not tripped. If I wait 2-3 days the circuit comes back on without me doing anything. Last week my wife hit the wall mounted garage door opener button (same circuit) and it kicked off the circuit. No breakers thrown. Three days later the circuit is back on without me touching anything. Is it time to call an electrician to install new circuits before I burn my house down? What could be the cause? Faulty cord? It's probably a 20 amp circuit but I never run more than one tool at the same time. Any suggestions?
 

jttheclockman

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Freddie

Not sure what you mean it kicks the circuit off. I am guessing there is no power on your chord or the door opener or anything else on the circuit. If what I said is correct then it sounds as if there is a loose wire and it is probably in the recptacle you are plugged into. Two things could be happening and neither of them is safe. The garage door probably is shaking the wall causing the connection to loosen. Two same senerio with a loose connection but now what is happening is the wire is getting heated because of the load you are putting on it by either using the saw or using the motor of the garage door opener because I bet they took the circuit for the opener out of the box that houses the receptacle. What happens is the wire cools down and now the circuit makes again and usually this will happen in a shorter time frame than 3 days but whatever. Thus no breaker trips but the circuit is intterupted. You definetly need to look into this and have any reptacle or junction box for that circuit checked and I bet you will find a loose wire. Good luck.
 

Rifleman1776

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Originally posted by edman2

Well, here is my problem. My shop is in my garage. Limited outlets. I have a long (longer than 30 ft) extension 12/3 cord with a triple outlet on the business end run the length of the garage. Lately when I start my miter saw it kicks the circuit off. Breakers are not tripped. If I wait 2-3 days the circuit comes back on without me doing anything. Last week my wife hit the wall mounted garage door opener button (same circuit) and it kicked off the circuit. No breakers thrown. Three days later the circuit is back on without me touching anything. Is it time to call an electrician to install new circuits before I burn my house down? What could be the cause? Faulty cord? It's probably a 20 amp circuit but I never run more than one tool at the same time. Any suggestions?

Freddie, if the circut breaker doesn't trip, you have a
Past time to call an expert. Yes, you do not wish to burn your house down.

Edit: the words were: DANGEROUS CONDITION
 

edman2

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John, Thanks for the tip. I will check the receptacles for a loose wire. I had assumed it was a heat/cooling situation but didn't know what would cause it.
Frank, Thanks for the advise. If I don't find a loose wire in the receptacle, I have made the decision to not use my power tools again until I can have an electrician trace down the problem for me. Sure would hate to burn up all my pen blanks!:D
 

leehljp

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I will jump in with my trivia question that is related.

What determines the maximum size of the breaker box that can be put on a house or building?

When I understood this basic concept, the 'big picture' of electricity distribution came into view for me. The answer is somewhat related to the idea of a #12 size extension hooked to an outlet with 14 wire inside.

The answer to the breaker box question is "the size/rating of the incoming wire" to the house or building determines the max size box that can be installed.
 
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jttheclockman

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Lee

Your question or answer or both are a little tricky. You can have a 24 circuit, 36 circuit or 42 circuit panel on that same feeder. You can have sub panels off that same feeder within code. So that is a broad statement. Also there is nothing wrong with using a #12 wire extension cord on a circuit that has a #14 feed. Just that you will or should know that circuit is only backed up with a 15 amp breaker. In fact it is advantagous to use a #12 for the simple fact as was previously mentioned you are taking out the voltage drop factor with the use of the cord to a certain extent.

I guess we have gotten off the beaten path of penturning abit here. Sorry about that.
 
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