# Extension cord will harm treadmill? **URL:** \ **Category:** Factual Questions\ **Created:** [January 29, 2017, 9:32pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530 "2017-01-29T21:32:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [January 29, 2017, 9:32pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/1 "2017-01-29T21:32:28Z")
The electric cord that came attached to my treadmill is about four feet short of where I want to plug it in to the wall. The manual says no extension cords should be used. Will a short (four foot) heavy duty extension cord ruin my treadmill or burn my house down? ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [January 29, 2017, 10:01pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/2 "2017-01-29T22:01:01Z")
> [@Mangosteen](#): > > The electric cord that came attached to my treadmill is about four feet short of where I want to plug it in to the wall. > > The manual says no extension cords should be used. > > Will a short (four foot) heavy duty extension cord ruin my treadmill or burn my house down? what’s the rated current draw of your treadmill? It should be either in the user manual or printed/embossed on the treadmill near where the cord attaches. ---
**Author:** ![busterpickle](https://avatars.discourse-cdn.com/v4/letter/b/258eb7/32.png) [@busterpickle](https://boards.straightdope.com/u/busterpickle)\ **Post date:** [January 29, 2017, 10:22pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/3 "2017-01-29T22:22:06Z")
Probably a safety precaution. In a house, the circuit breakers are rated for 100% for (I think) 15 minutes, and 50% current draw can be sustained indefinitely. I would be surprised if it needed that much though. Any ways, I think an extension cord rated for the branch circuit would be fine, which would be 15 amp. If you want to be a belt and suspenders type person you can get one rated for 20 amp. After that the cord will have a different plug. OOC, what make/model? ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [January 29, 2017, 10:24pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/4 "2017-01-29T22:24:30Z")
> [@Mangosteen](#): > > Will a short (four foot) heavy duty extension cord ruin my treadmill or burn my house down? Heavy duty is the right thing to use here. Use a good quality ‘appliance cord’ that’s no longer than required. The manual says to not use them because people will use flimsy cords that get too hot or long ones that get wrapped into the tread belt and pull the family dog into the gear train. It’s safer and easier for them to say to never use one rather than trying to detail which ones are suitable. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 29, 2017, 10:57pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/5 "2017-01-29T22:57:13Z")
How much current does the treadmill draw? Regardless, I love overkill. If you have a 20 A receptacle, I would use [this](https://www.amazon.com/NEMA-5-20-Extension-Power-Cord/dp/B00CDVOBOK/) extension cord. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [January 29, 2017, 11:02pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/6 "2017-01-29T23:02:50Z")
> [@electronbee](#): > > Probably a safety precaution. In a house, the circuit breakers are rated for 100% for (I think) 15 minutes, and 50% current draw can be sustained indefinitely. > > I would be surprised if it needed that much though. Any ways, I think an extension cord rated for the branch circuit would be fine, which would be 15 amp. If you want to be a belt and suspenders type person you can get one rated for 20 amp. After that the cord will have a different plug. > > OOC, what make/model? Its a Precor 9.31, 8 years old. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [January 29, 2017, 11:02pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/7 "2017-01-29T23:02:57Z")
as an example, the treadmill my mom has is marked 120VAC / 60Hz / 15A. which is probably the peak current, for a treadmill that would be in short “spikes.” a heavy duty extension cord for that rated current would probably be OK. definitely don’t want to use one of those thin, flimsy ones like for Christmas lights. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [January 29, 2017, 11:04pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/8 "2017-01-29T23:04:53Z")
> [@Crafter\_Man](#): > > How much current does the treadmill draw? > > Regardless, I love overkill. If you have a 20 A receptacle, I would use [this](https://www.amazon.com/NEMA-5-20-Extension-Power-Cord/dp/B00CDVOBOK/) extension cord. I saw this type has a four foot cord. > **[Amazon.com: C2G 4FT Premium Universal Extension Cord - Power Extension Cord for...](https://www.amazon.com/C2G-29930-Outlet-Extension-Compliant/dp/B001GUVYUS)** > > Buy C2G 4FT Premium Universal Extension Cord - Power Extension Cord for TV, Computer, Monitor, Appliance & More (29930): Everything Else - Amazon.com ✓ FREE DELIVERY possible on eligible purchases ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [January 29, 2017, 11:08pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/9 "2017-01-29T23:08:07Z")
> [@jz78817](#): > > as an example, the treadmill my mom has is marked 120VAC / 60Hz / 15A. which is probably the peak current, for a treadmill that would be in short “spikes.” a heavy duty extension cord for that rated current would probably be OK. definitely don’t want to use one of those thin, flimsy ones like for Christmas lights. Mine is marked 120 VAC 50/60 Hz 12A ---
**Author:** ![JKilez](https://avatars.discourse-cdn.com/v4/letter/j/e5b9ba/32.png) [@JKilez](https://boards.straightdope.com/u/JKilez)\ **Post date:** [January 29, 2017, 11:18pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/10 "2017-01-29T23:18:05Z")
> [@Mangosteen](#): > > Will a short (four foot) heavy duty extension cord ruin my treadmill or burn my house down? To be safe, you should use an extension cord made with 14 gauge or 12 gauge wires. Most short length extension cords are 16 gauge or higher. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 30, 2017, 12:00am UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/11 "2017-01-30T00:00:41Z")
> [@JKilez](#): > > To be safe, you should use an extension cord made with 14 gauge or 12 gauge wires. Most short length extension cords are 16 gauge or higher. Yea, whenever I need to purchase a “permanent” extension cord for a “high power” device that has a 15 amp [NEMA 5-15P](https://sgcdn.startech.com/005329/media/products/gallery_large/PXT101Y.C.jpg) plug on the power cord, I will first try and find a cord with 12 gauge wires. If I can’t find a cord (in the length I want) with 12 gauge wires, then I’ll opt for a cord with 14 gauge wires. (An extension cord with 14 gauge wires will work fine, but I like overkill. I’m weird that way.) Keep in mind that short extension cords with 12 gauge wire will sometimes have a 20 amp [NEMA 6-20P plug](http://xiongrun.co/wp-content/uploads/2015/03/301G-NEMA6-20P.jpg). So even if your appliance has a 15 amp (NEMA 5-15P) plug, the receptacle will need to be [20 A](https://s3.amazonaws.com/cesco-content/unilog/Batch10/NULL/136969-ProductImageURL.jpg). ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [January 30, 2017, 12:07am UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/12 "2017-01-30T00:07:58Z")
> [@JKilez](#): > > To be safe, you should use an extension cord made with 14 gauge or 12 gauge wires. Most short length extension cords are 16 gauge or higher. the nice thing is- at least at the major home improvement retailers- the packaging usually is clearly labeled with the wire gauge; you don’t have to inspect the cord itself for any hard-to-see markings. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [January 30, 2017, 12:33am UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/13 "2017-01-30T00:33:46Z")
I have safely used extension cords with appliances, including oil-filled space heaters that say never, never use them. I always use heavy duty ones and check that they are a gauge up from the appliance. Like someone said above, the warning is mainly because people will use flimsy ones for small lamps, and they’ll catch fire. Another concern is that a long extension cord, longer than you need, should not be left coiled. It should be laid out so air can circulate around it in case it does get a little warm. It is hard to find short, heavy-duty cords. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [January 30, 2017, 3:07am UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/14 "2017-01-30T03:07:11Z")
Another problem with long thin extension cords with multiple junctions, is that there may be too much voltage drop during the start-up, when the motor draws 5-10 times as much current. This can, in extreme cases, cause the motor to burn out. I dislike extension cords and power boards because they used to be involved in so many fires (i’m getting old). I would take the covers off and see if i could wire in a longer cord. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [January 30, 2017, 1:28pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/15 "2017-01-30T13:28:31Z")
When they say don’t do this, don’t do this. The “But it worked for me.” stuff _is not at all good advice_. For a device like a treadmill there can be substantial loss of power in the extension cord which is hard on the motor and it will fail early. Note: the point of failure is most likely to be the treadmill, _not_ the cord. Corded weed cutters are a well known example of this. People use the wrong gauge extension cord and the motor burns out. In theory you could use the a cord with the right gauge, the right plugs and the right length. Do you know how to calculate what “right” is here? I think not. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 30, 2017, 1:32pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/16 "2017-01-30T13:32:54Z")
But what happens if you take off? ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [January 30, 2017, 3:05pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/17 "2017-01-30T15:05:48Z")
> [@ftg](#): > > When they say don’t do this, don’t do this. The “But it worked for me.” stuff _is not at all good advice_. > > For a device like a treadmill there can be substantial loss of power in the extension cord which is hard on the motor and it will fail early. If I get a short straight cord with the same gauge as what is supplying power to the socket on my wall, how far off “right” is it possible I am? ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [January 30, 2017, 3:30pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/18 "2017-01-30T15:30:51Z")
I’m hesitant adding anything here … seems the manufacturer already attached a cord and did the math … it’s already at the safe limit for length and/or size … if they say don’t use an extension cord, then maybe this takes the matter over the safety limit … perhaps the OP could describe the existing cord in terms of length and size … Copper wire makes for a good conductor, but not a perfect conductor … there is a little resistance and the energy of the voltage drop is dissipated as heat … so the longer the cord, the more resistance and more heat … the smaller the wires, the more resistance and more heat … So, I’m running a little electric chainsaw at the end of 200 foot of extension cords (first 50’ = 10 gauge, rest = 12 gauge) and things were getting quite warm … like melting the plastic end caps warm … maybe I could have caught something on fire if I hadn’t cut through the cord when I did … My advice … move your treadmill the four foot closer to the outlet you want to use … it doesn’t matter how low the risk of burning down your house … the consequences of such to far far too great to chance it IMEIO … ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [January 30, 2017, 8:02pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/19 "2017-01-30T20:02:06Z")
Find out the amperage, and then explicitly get an extension cord that is rated to handle that amperage. IF you can’t find it, try to match the amperage that corresponds to your house wiring, usually 15 amps. Yes, that will mean the gauges mentioned above, but I would not go just by the gauge. The lower gauge, the better, however. The reason you are told not to use an extension cord is that the vast majority are not so rated, and can get incredibly hot or short out. It is not some global restriction. It wouldn’t make sense if it were–your house wiring is essentially just an extension cord that’s permanently in place. Sure, there is the added issue of the extension cord moving around. But, first off, you can minimize this yourself. Plus, the cords are usually quite thick and resist any sort of sharp bending, let alone any damage. (Still, avoid kinking the cords) As long as the cords (including the plug ends) do not get hot, it is fine. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [January 30, 2017, 11:40pm UTC](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530/20 "2017-01-30T23:40:25Z")
But then if I plug the treadmill into an outlet in my living room, the electricity has to run through 30 feet more wire than if I plug it into an outlet in my kitchen. Do I have to concern myself with this? What difference does it make if the wire the electricity runs through is inside the wall (house wiring) or outside the wall (extension cord) when the wire is the same gauge? [Next page](https://boards.straightdope.com/t/extension-cord-will-harm-treadmill/778530.md?page=2)