How Is Your Layout Connected to Your Breaker Box? Filtered? Grounded?

I don't know if you need to put another spike in the ground, the main box is already grounded to earth and any additional boxes would be. If your 20 seems overloaded, then likely you would need a sub panel (I won't need one, my box has a lot of open breaker slots, and I have 200 amp into the house). In terms of what size breakers, that depends on what size wiring you use, since you are wiring new I would use 12 gauge Romex and that would allow for a 20 amp breaker (that is code). If you happen to have a ton of 14 gauge romex you want to use, then use 15amp breakers and have several circuits, will give you the same thing. Having several smaller circuits means you would need to wire those circuits, extra work. I would likely wire 2 20 volt circuits rather than 3 15 amp circuits, 2 20's would give me plenty of room for expansion and I would need fewer UPS's to cover all my train circuits.

One thing to be mindful of is total power consumption in the house. Doesn't sound like that is a problem now (if you are running everything over a single 20a circuit, and it doesn't pop, and the main breaker doesn't pop, you likely are fine), but if you are planning on adding more power draining devices you might want to take a look at the size of your service and see if that needs expanding (likely not, most houses these days seem to have 200A service, but older houses may be 100).

As far as filtering power, I would use a UPS on each separate circuit that powers your trains (right now you have one). Verify that it is the type of UPS that powers off the battery continuously and charges, not one that cuts in. Not so much for the back up power, but rather as far as I know that gives the best voltage clamping, that the battery----inverter-----outlet is going to be the cleanest . You would need to find a UPS with the wattage to handle a 20amp or 15 amp max circuit (2kw or 1.5 kw, respectively), but the good news is they aren't ridiculously expensive. You don't need a heavy duty that you would use on a sub pump or the like that will last for hours, you really only want it for the voltage clamping I would presume. I have used APC UPS units I got for like 100 bucks at CDW and they have kept my sensitive electronics protected. At one point I kept burning out cable modems and my wifi routers with power surges (the power in my area was incredibly dirty at the time), once I went to UPS, everything has been fine.

I put in a 20 amp breaker and ran 12 gauge Romex to the attic/train room.  That supplies lighting, gable end fan and the layout as well as two Hunter ceiling fans (in other rooms).  Two ZWs and power for accessories are plugged into a power strip with surge protection.

Exactly how big is your layout?  A 20A circuit supports 2,300VA or well over 2,000 watts!  You need a pretty large layout with lots of power hungry stuff running to tax that circuit.

I agree with John. You need to do some math. Add up all the watts that you are now using to see where you are. They should all have a label showing power usage. Even if that comes close to your capacity, they would all have to be maxed out to reach it, which would be very rare. What size wire  you used will determine your limit, as @bigkid says. If you didn't use 12awg, you can't figure on 20 amp protection. You can also find plug in meters to determine usage. Search Amazon for Kill a Watt or similar.

I have four Powerhouse 180 tranformers as well as a couple of 50W MTH bricks, and of course the Legacy brick and several wall warts for stuff like the LCS and MTH WiFi.  When I was running four trains with smoke and even eight passenger cars with incandescent lighting, my meter was right at 300 watts.  I have my 24 x 12 layout powered by a single 15A circuit, and I seriously doubt I'll ever come remotely close to overloading it.  You may be overthinking the power thing.

Ditto.  If the breaker isn't tripping you're good to go. Depending on your comfort level around electricity, you could replace the 20 with a 15 amp breaker if there is doubt you have real 20 amp coverage, but I doubt that would trip either all things being equal.

If you're on a backup generator be sure that circuit is on the transfer switch.

I have a 15 Amp circuit dedicated for the layout - room outlets and lighting are on other circuits.  I have a 40' by 50' layout with DCS using two MTH Z4000 for track power and a computer power supply for DC with 4 isolated outputs for 12 VDC.  I have never had an issue that the layout drew too much current.   I use no special filtering or UPS, in my opinion over kill.

If you have unreliable power, maybe you want a UPS or filtering, but I would expect it to cause issues with other things in your house before the trains.

As many have said  a single 20A circuit should more MORE than enough. I am unsure on the UPS for the layout in my head it seams quite excessive but then again I don’t know how reliable or unreliable your power is. One thing I would for sure look into is a whole house surge protector. Takes care of a lot more than just trains, as a HVAC/R contractor we recommend them any house we walk into for our equipment; it’ll sure protect your other Applinces too.

If you're going for a UPS, you'll probably want one that outputs a pure sine wave unit as you'll be feeding transformers with the power.

Cyberpower OR2200PFCRT2U

Cyberpower CP1500PFCLCD

A single 20 A circuit with 12/2 NM-b (romex) wire would be more than enough for most layouts. As others have stated, 15 A w/ 14-2 would be as well. Make sure you have high quality receptacles at the end and use the screw terminals, not the push-in connections.

As per the NEC (National Electrical Code), all building services must be grounded to the water main AND a supplemental 8' driven ground rod. If the building has a plastic water main, then two rods are required, spaced 6' apart,  and the piping in the house must be bonded with # 6 copper. A 200 A service requires a # 4 wire to the water main, anything lower, # 6 is code. Always make sure that the pipe where the ground clamp is attached is clean for a solid connection. All service grounding connections must be bonded together in the main panel board. If your main breaker is separate from the panel (outside with the meter), then the grounding all goes to that panel. Grounding and bonding are unique terms in the code, to much in the weeds to go into here.

DO NOT RUN LOOSE GROUNDS TO ANY OTHER PIPES OR RODS!  This can cause all sorts of problems down the road.

For surge protection, a good UPS is fine but overkill unless you really need to run your trains in a power failure. A good quality power strip will handle most transients that could affect our trains. A whole house TVSS (transient voltage surge suppressor) , can be installed in your main panel to protect everything. Transient protection should be done in layers for the best results. If you are having constant problems, call your local utility, they can investigate their side for possible problems with the grid.

As always, consult a local licensed electrician if necessary.

Bob (licensed master electrician since 1993)

Thanks for all your comments. My city of Pittsburgh house is just shy of 100 years old. It has only 100A service. But then we don't have a lot of big power drain stuff. The breakers almost never trip. The layout breaker (on which I also have my main workbench and workbench lighting) has never tripped.

But given the age of the electrical installation. I am concerned that the ground might not be up to spec given the many years of service it must have seen by now. Do you think I need to test the quality of the ground at my breaker box? How do I do that? I assume a Simpson 260 on the low ohms setting won't do the job?? <grin>

Otherwise I am probably okay--and as John suggests--probably worried when I don't need to be.

Don

I'd probably do a low voltage current test of the ground to the main circuit box if I were suspicious of the quality of the ground.   The ground pin on the outlets should be bonded to the circuit box as well as the neutral at the main circuit box.

If the service is really 100 years old and hasn't been upgraded, does it even have 3-prong outlets?  3-prong outlets only became standard in 1969.  At that point, many houses still only had 2-prong outlets.

Don, my grandparents house in Mt Oliver was built in the 1920's. It had knob and tube wiring with a fuse box. In the 1950's it was rewired with two conductor romex, no ground. The two prong outlets were left in place as well as the original fuse box. It met the code in effect in the early 1950's.

If your Pittsburgh house has three conductor romex with three prong outlets and a circuit breaker panel it was likely rewired in the 1960's or later.

Never even thought about this. My layout is in a single spare room and all power (2 z4ks, 4 Z1000s) feeds into a pretty good heavy duty, surge suppressing power strip and then is fed into the wall. The room is hooked up to a 20 amp breaker in the garage.  since the  house was built in the past 30 years, I assume the breaker box is grounded properly and up to modern specs. Everything Bob and others have written might as well be Chinese to me, LOL!

Anything built after 1969 that adheres to the NEC will have three-wire grounded outlets.  In the 70's and 80's, the ground was a smaller gauge wire, but it was there.  Nowadays, the NEC specifies the ground is the same size wire as the current carrying wires.  Not sure when the change to full sized ground wires went into effect, but it was a long time ago.  My previous house that I built in 1989 had the full sized ground wires for all the circuits.

Yes, it has 3-conductor outlets and 3-wire romex where the wire is visible. The detached garages still have 2-wire knob-and-tube! One cause for concern is that the wiring has been "fiddled with" over the years. I'll not bore you with the details but suffice to say that they used to cook and sell meat balls here! I sure wish they still did--I bet they were tasty!

Don

Just having re-read the original post, I believe that unless the poster has a 30' x 50' building with a massive layout that runs 10+ trains at once - half of those being lighted passenger cars - anything beyond a normal 15A breaker protected circuit is total overkill. Just my opinion.

@Don Merz 070317 posted:

...  The layout breaker (on which I also have my main workbench and workbench lighting) has never tripped.

Don

I'm set up the same way as you are, layout, work bench, bench lights, small power tools, battery chargers, soldering irons, space heater in winter, etc. are all on one 20 amp breaker.  It's all been working just fine and has never tripped.

@Don Merz 070317 posted:

Yes, it has 3-conductor outlets and 3-wire romex where the wire is visible. The detached garages still have 2-wire knob-and-tube! One cause for concern is that the wiring has been "fiddled with" over the years. I'll not bore you with the details but suffice to say that they used to cook and sell meat balls here! I sure wish they still did--I bet they were tasty!

I'd probably check the grounding as I described, but other than that, I suspect you are fine.

Current consumption for trains and accessories using 12-25 volts is a whole lot different than current draw on the 120 VAC side of the transformers.  As an example, that train pulling 8 amps @ 20 volts might put only 1 amp load on a 120 volt circuit. (Yes, I know this can be calculated and transformer loss added in, but I'm too lazy to do that today). Don't add up all the currents for your trains and accessories and think that is the current draw from your breaker box. It's not.  As the voltage drops, the current goes up, and of course at 120VAC on the other side of the transformer, the current will be very low.

A 20A circuit breaker is plenty large enough for trains.

Dale

I know I did an overkill but my train room had two circuits coming to the room, I had room in my breaker box for more ( still do have a couple of slots open even now) but I ran two more circuits so I have one circuit per wall. 

@gunrunnerjohn posted:

I'd probably check the grounding as I described, but other than that, I suspect you are fine.

Not sure what a low voltage current test is.  Why not just use a receptacle tester to check the ground?

@Lehigh74 posted:

Not sure what a low voltage current test is.  Why not just use a receptacle tester to check the ground?

Quite simple.  A receptacle tester just tells you there's some continuity, it doesn't tell you if it's a solid connection.  A low voltage current test is using the ground wire to carry some real current to know it's actually solidly connected.  Truthfully, the little testers people run around with "checking" outlets are somewhat of a joke, I want to know that ground wire actually is capable of carrying enough current to trip the circuit breaker.

@gunrunnerjohn posted:

Quite simple.  A receptacle tester just tells you there's some continuity, it doesn't tell you if it's a solid connection.  A low voltage current test is using the ground wire to carry some real current to know it's actually solidly connected.  Truthfully, the little testers people run around with "checking" outlets are somewhat of a joke, I want to know that ground wire actually is capable of carrying enough current to trip the circuit breaker.

John is correct. Those testers just check for correct wiring, reversed hot/ neutral, reversed neutral/ ground, and the presence of a ground. Not the quality of the connections.

Protection on the line side is not nearly as important as on the load side of our transformers.

Bob