Just get an extension cord suitable for the power requirements.  A heavy duty outdoor cord would probably be a good option.  It should be a 3 prong cable and I would avoid it running where people walk or get a cable through to put it in.  I would then see what it would take to drop a couple of circuits in your unfinished basement.

I agree with Marty. A proper extension cord will definitely work. I’m using one for my setup. In a previous life I was a journeyman industrial electrician so I’m very comfortable with what I’m using and what the drawbacks could be.

Even though it’s a relatively short run from the nearest 20 amp circuit outlet I’m using a heavy duty exterior grade three conductor #12 wire cord. It’s really more than I need, and that’s a good thing. You definitely want that 3 prong cord plugged into a receptacle that accepts a three prong plug. NO - 3 to 2 prong hole adapter! This is important not only for safety but down the road you’ll find that it can be critical to the proper operation of some sensitive electronic equipment.

That cord should be considered “temporary only”. Cords can become damaged in hidden places. Pets can chew them. Water can get into the end laying on the floor, etc. Also consider a quality power strip that is properly mounted off the floor. Cheap is not good here. You may be plugging some expensive equipment into it. As yet, I’m not sure how well the system will work with a GFI installed, but on a bare concrete floor with barefoot children playing with electrical things, well… I’d install one ahead of the extension cord.

In the year i've been into it, I’ve gotten about 300 ft. of track, 2 legacy diesels and my trusty Hudson. I’ve got many cars that came with incandescent lights that pulled a lot of current at that 18 volts ac. I’ve since changed them to LED lighting. Almost no current draw now. With everything running I’m pulling about 6 amps. Since I’ve just started with this hobby a year ago, I don’t have any buildings yet. But I well. Lots of power needed with another transformer down the road.

Having said that, as an example, 10 amps at 18 volts is 180 watts, (Volts times Amps = watts), through the system. That 180 watts divided by 120 volts on the other side of the transformer is only 1.5 amps that travels through that extension cord. 20 amp extension cord Over Kill? Perhaps. But virtually no voltage drop from the house receptacle to the transformer using that tough cord. That leaves lots of power growth in my system.

Perhaps most important, Have some fun like I’m having!

Bob

For a reasonable cost (especially when you compare it to the cost as you start buying locomotives) have an electrician add a new 20A breaker to the home electrical system you have, run some wire in conduit, including lighting.

Is your electric service panel in the unfinished part of the basement?  If so, an electrician installing a new outlet is a minor project.

Another option is to use both parts of the basement.  I have finished and unfinished and I am using both.  I cut out drywall to make a connection between the two areas.  It fairly trivial for a drywall guy to patch if you later want to move.

@Mike Wyatt posted:

For a reasonable cost (especially when you compare it to the cost as you start buying locomotives) have an electrician add a new 20A breaker to the home electrical system you have, run some wire in conduit, including lighting.

Agreed. Extra outlets always come in handy, and you won't regret having good lighting either. It will be money well spent. I remember when I started construction of my train room, I thought I was crazy to have lighting and outlets installed, but every time I walk into my train room, I'm glad I did.

@Mike Wyatt posted:

For a reasonable cost (especially when you compare it to the cost as you start buying locomotives) have an electrician add a new 20A breaker to the home electrical system you have, run some wire in conduit, including lighting.

@Mike Wyatt, amen !   The OP would be well-advised to step back for a moment & consider all the electrical needs for a nice train room, such as lighting, train power and sufficient outlets for power tools, vacuums, etc.

Rich

IF you decide to use an extension cord temporarily or long-term, I recommend using an extension cord that is 12AWG. If you have to shop for the cord you will be tempted by the 14~16AWG cords because the 12AWG cords are significantly more expensive since covid - they used to be roughly under a buck-per-foot, now they are about $2+ per-foot. Your train table is very unlikely to use enough amperage to cause any trouble/stress for the outlet/circuit you plug into - but the 12 gauge wire will ensure that your transformers and equipment get all the 'juice' they deserve.

Good luck!

EDIT:

gunrunnerJohn & ACDXRob (below) are both correct 👍 in my job it is not uncommon for me to discover homes that have something mickey-moused electrically. I generally apply an abundance of caution.

The whole house is most likely wired using #14 for the outlets, so I'd expect a #14 extension cord is probably sufficient.  One thing to do is keep the length of the extension cord no longer than needed.

A 15 foot #14 extension cord carrying 10 amps drops less than a volt, not a measurable problem I suspect.

It just occurred to me reading this post that my O27 layout built in 1971 has been powered by an extension cord this entire time. I reach behind me from the control panel to a workbench strip to plug it in, and then flip the rocker switch on a period(all metal) plug-in strip to power up. The power strip keeps all the transformers in phase, the power strip on the workbench is wired with 14-2(+G) romex, but the layout is powered by almost three extensions this whole time... never gave it a thought, probably won't change anything now!

At work, insurance companies, not OSHA, want no electrical extension cords. Rather, if they find extension cords in use, they charge more. So we are supposed to absolutely have to need one, which happens time to time. I believe its not an electrical thing, its a trip hazard, and again I recall a presentation on safety and the #1 type of accident in a factory is trips and falls.

So if you run the extension cord from one room to another, figure out how to not trip on it.

@illinoiscentral posted:

At work, insurance companies, not OSHA, want no electrical extension cords. Rather, if they find extension cords in use, they charge more. So we are supposed to absolutely have to need one, which happens time to time. I believe its not an electrical thing, its a trip hazard, and again I recall a presentation on safety and the #1 type of accident in a factory is trips and falls.

So if you run the extension cord from one room to another, figure out how to not trip on it.

Well, the only extension cord I have for my layout is the one that goes from the outlet to the power box of my Mianne LiftBridge.  The actual layout power does have a cord that's under the layout that goes to a multi-outlet power strip, but nobody is walking under there.

Are you sorry you asked yet?

Since both of my layouts are freestanding on a concrete slab floor, I have no option other than to use "extension cords" to power them. However, both are long-cord heavy-duty power strips, one running through a heavy-duty beveled wood wire channel on the floor, and the other routed through the open rafters and down a support pole to the layout. Both are well protected from accidental contact or damage, and as others have detailed, both are well suited to handle the layouts' power demands.

I recommend biting the bullet and have an electrician install a couple outlets. you'll be glad you did.

Wow, I did not expect this much feedback! Thanks for all the input, sounds like I'll be using a heavy-duty extension cord

@MartyE posted:

Are you sorry you asked yet?

Never!

Thank you all again!

Edit: I will think about having extra outlets installed though

@0-Gauge CJ posted:

Wow, I did not expect this much feedback! Thanks for all the input, sounds like I'll be using a heavy-duty extension cord

And I can’t believe a simple question about an extension cord generated all this fuss.

If you are going to run an electric heater consuming 1,500 watts, then that 10 or 12 gauge extension cord is needed. But a small train layout consuming less than 200 watts sure doesn’t need a 10 or 12 gauge extension cord!

To mitigate the trip hazard, use a cord cover.  Search for "floor cord cover".  My cover is secured to the concrete floor with duct tape.  Double-sided tape can also be used.

@Rich Melvin posted:

…..But a small train layout consuming less than 200 watts sure doesn’t need a 10 or 12 gauge extension cord!

But does it hurt to use a 10/12 gauge cord for his small layout?  Setting aside cost and heavier/stiffer wire, is there a performance issue?

@CAPPilot posted:

But does it hurt to use a 10/12 gauge cord for his small layout?  Setting aside cost and heavier/stiffer wire, is there a performance issue?

The only thing "hurt" by using a larger gauge extension cord is your wallet. As for a performance issue, there is none.

You won't notice any difference in performance under 50 foot of 14awg, - you can measure it... but you won't notice it 👍. You might be able to detect a difference at 100+ ft of 14awg - 🤔-maybe (shrug)... But that would be only for a sizable table running multiple transformers & trains, something more modest like my table with a ZW-L with an old R type would still run just like it should. And - like I said above, I am guilty of using an abundance of caution AND you would be hard pressed to find anything below 14 gauge in my life, only because am frequently using cords for my work with saws/drills/air-compressors and the like that WILL have a detectable performance difference. I didn't mean to set off or start any confusing discussion 😉

@Rich Melvin posted:

The only thing "hurt" by using a larger gauge extension cord is your wallet. As for a performance issue, there is none.

Agreed, but such a cord is also significantly bulkier and stiffer than a lighter duty one, making it a bit harder to bend around turns, etc. Bottom line is, if you *have* such a heavy duty cord already at hand and can afford to retire it to permanent duty powering your layout (or use it for a temporary lash-up), sure, go for it, but if you are trying to figure out the optimum/appropriate cord to purchase, over-spec cords offer no practical benefit and some tangible detriments IMHO. Not a hard choice ISTM . . .

TMI...TMI...TMI...

TMI??  AMEN!!

I never would have believed that a question about an EXTENSION CORD could generate so much additional - and mostly useless - information. 

@MartyE posted:

Are you sorry you asked yet?

You guys are late to the TMI party.

I'm amazed they are still plug-in away at it!

@Darrell posted:

I'm amazed they are still plug-in away at it!

Oh, it's all just an extension of the original question . . .

Time to pull the plug ...

Buy a good one and only plug it in when you're using it.

For some reason, many model train hobbyists tend to both overthink and overbuild. Model train layouts, even fairly large home-type layouts, do not have excessive electrical needs, and the layouts do not need to be constructed so you could park a 1:1 scale car atop them. There may be an occasional exception, but they are few and far between.

@Allan Miller posted:

For some reason, many model train hobbyists tend to both overthink and overbuild. Model train layouts, even fairly large home-type layouts, do not have excessive electrical needs, and the layouts do not need to be constructed so you could park a 1:1 scale car atop them. There may be an occasional exception, but they are few and far between.

You should've been there when we took down the layout of our beloved Marty Fitzhenry. Extension cord?? Ha!! He had an entire separate breaker box just for his layout. And his benchwork was rock-solid. I spent a good amount of time on top of the benchwork removing the track from his massive passenger yard, and "sturdy" is an understatement. A hurricane could've wiped out Dedham, and his benchwork would've survived.

To each his/her own.......

Just now readying -all of this...  lol.  Yes, all this is solid and correct advice.  My takeaway is ---most of the crew on here is just dying to be helpful.   Awesome, thanks fellas for making this a solid place to hang out.

@Allan Miller posted:

For some reason, many model train hobbyists tend to both overthink and overbuild. Model train layouts, even fairly large home-type layouts, do not have excessive electrical needs, and the layouts do not need to be constructed so you could park a 1:1 scale car atop them. There may be an occasional exception, but they are few and far between.

I am amused by the massive electrical overkill most layouts have, including mine.  I have four PH180 transformers powering around 500 foot of track.  Everything eventually plugs into two industrial power strips and then to a 15A single outlet.  I stuck a watt-meter on the power connection at the outlet and got four trains running, all with smoke.  Then I powered up a couple more trains in the freight yard and just let them sit there.  The watt-meter read less than 250 watts at it's peak reading, less than 20% of the rated capacity of the 15A 120V circuit.  I haven't thought about power issues since.

My goal was to never have to think about adding power, and as near as I can tell, I accomplished that goal.

@gunrunnerjohn posted:

I am amused by the massive electrical overkill most layouts have, including mine.  I have four PH180 transformers powering around 500 foot of track.  Everything eventually plugs into two industrial power strips and then to a 15A single outlet.  I stuck a watt-meter on the power connection at the outlet and got four trains running, all with smoke.  Then I powered up a couple more trains in the freight yard and just let them sit there.  The watt-meter read less than 250 watts at it's peak reading, less than 20% of the rated capacity of the 15A 120V circuit.  I haven't thought about power issues since.

Just curious, John -- I've always assumed the pre- and postwar stuff like I mostly run is significantly less energy efficient (e.g., it draws more current and consumes more power than its more modern equivalents) and thus a layout heavy with this kind of equipment needs a bit more safety margin. I haven't done the kinds of direct measurements you took (mostly relying on the lack of significant "browning out" when I add load), but have you seen any confirmation or refutation of my working hypothesis?

@Steve Tyler posted:

Just curious, John -- I've always assumed the pre- and postwar stuff like I mostly run is significantly less energy efficient (e.g., it draws more current and consumes more power than its more modern equivalents) and thus a layout heavy with this kind of equipment needs a bit more safety margin. I haven't done the kinds of direct measurements you took (mostly relying on the lack of significant "browning out" when I add load), but have you seen any confirmation or refutation of my working hypothesis?

Well, I do know that the open frame AC motors do suck down a lot more power, a dual motored diesel can easily hit 2 amps and maybe a bit more.  OTOH, two amps at 18 volts is 36 watts!  So, running ten of those would be 360 watts, toss in another 15% for transformer efficiency, and you're still running at 20% of the available power, maybe 3 to 4 amps max on the 120V side.  Also, you're not normally running them at the full 18 volts, so even that is a generous power budget.

Fifty years ago a 14 gauge line and a 15 amp breaker handled two ZWs and one KW to run several post war and MPC trains and accessories at the same time,  plus an old  Marx transformer for lighting.   NO PROBLEMS EVER.   

Today our module club runs two Z4000s, a TIU, a Legacy base and at least six small transformers for lighting and accessories on one 15 or 20 amp circuit (depending on the building) using a long 12 gauge extension (distance can matter).                     NO PROBLEMS EVER.     

How did this get so complicated?  Remember:  "Model Railroading is Fun"

Earl

@gunrunnerjohn posted:

Well, I do know that the open frame AC motors do suck down a lot more power, a dual motored diesel can easily hit 2 amps and maybe a bit more.  OTOH, two amps at 18 volts is 36 watts!  So, running ten of those would be 360 watts, toss in another 15% for transformer efficiency, and you're still running at 20% of the available power, maybe 3 to 4 amps max on the 120V side.  Also, you're not normally running them at the full 18 volts, so even that is a generous power budget.

Thanks, John, that pretty much tracks my seat-of-the-pants "engineering" sense, so I guess I won't call up and increase my home fire insurance limits just yet . . .

@Conductor Earl posted:

How did this get so complicated?  Remember:  "Model Railroading is Fun"

Well, yes, as it turns out, the issue is less urgent and potentially catastrophic than it might have seemed up front, but I'd *much* prefer any such question be asked and answered than have the poster fail to realize there *might* be a question to be answered! The multitude of answers is IMHO partly the fact that the subject is well within the competency of many of the members, and has enough variations or aspects that many of us can each add our two cents.

Yes, model railroading *is* fun, but not if you burn down your house in the process, or get mocked just for trying to help a fellow hobbyist. Chill, folks . . . 

Looks like the extension cord issue has been answered.  I am wondering why you have an unpowered outlet.  Had to have been powered at some point or why put it in.  I would find out it it was disconnected on purpose or if there is a problem waiting to happen.