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Hello, All!

I'm new to the group and this is my first time posting. I apologize in advance if I didn't do it properly.  I am in the process of building a layout with two main loops using Legacy command.  I don't plan on running any conventional trains.  I do plan on adding DCS once the WTIUs are available (someday, lol).  I just completed my first loop and started on the second.  I would like each loop to be it's own power district powered by 180 watt bricks.  The brick powering my first loop is connected to a TMCC direct lock-on which is then connected to the track via bus wire with power feeds every 8-10 feet and on each leg of my turnouts.  I have no issues with my first loop but this is where I am stuck.  I started working on my second loop, powered by a 180 wat brick, connected to a TMCC lock-on, etc.  I am attempting to connect my loops (they run parallel) using pairs of Atlas #5 switches.  Based on every online article I can read or watch, I understand that only the center rail needs to be insulted in order to separate my power districts.  However, I am running into an issue when my engine(s) and consist go from one power district (loop) to another.  The engine(s) short out or sputter.  Most online resources include a diagram with multiple power supplies and a TIU.  Because I don't have a TIU yet, I am guessing I am doing something wrong.  Based on my current configuration (2 bricks and 2 TMCC lock-ons) am I correct that only the center rail needs insulated?  Do I need to phase the power bricks in some way (IE run a wire from the common terminal of one TMCC lock-on to the common terminal of the other TMCC lock-on)?  Any help and suggestions will be greatly appreciated! 

Thanks,

Karl

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Yes, you need to phase your bricks.

ANYTIME you have more than one power source (example- 2 different bricks) you need to ensure phasing is tested and that you understand why.

It's this simple, if a transformer puts out 18V, and then you have 2 transformers, and by nature of 3 rail track, the outside is common, then if they are out of phase, the train crossing that point will see 18+18=36V!!! We warn on a regular basis that many Lionel manual state to never exceed 18-19V.

Second, if you enable anti-derailing function of the switches using insulated rail sensing sections- you need to understand where those insulating pins go too.

Again, let me explain. You should natively have the outside rails connected on your loops. Yes, in the specific switch area, if using the insulated rail method for detecting a train and throwing the switch then there could be insulating pins in an outside rail. That said, again, the one thing in 3 rail is that all tracks are expected to be common outside rail. So yes, either using a wire or the tracks themselves- effectively both "TMCC lock-on" devices, the outer rails should be common and adding a wire to ensure that is not a bad thing.

However, phasing is then measuring the center rail of one loop VS the other loop. In other words, with a meter set to AC Voltage, if you measure outside rail to center rail you should get expected 18V. However, if you measure center rail of one track, to center rail of the other loop, there should be near 0V no more than 2-3V maximum difference given the 2 power sources. If you see 30+ V, then the 2 bricks are out of phase and one of them the power cord should be swapped 180 degrees into the outlet or power strip. Also, a good idea to mark both the power strip and each plug to indicate the proper direction to plug in for correct phasing.

Thanks for the help, everyone!  I think I’m following what Vernon is suggesting but I want to be sure.  1 - I need to run a wire from one common terminal to the other common terminal of my TMCC lock-ons.  2 - only the center rails where the turnouts connect should be insulated.  I am attaching a photo of how I have my turnouts connected now along with my track plan.  
Thanks again!

Karl2A8A1ADE-A29E-485A-9A36-2DB9A6F804347D00C170-EBCB-4F56-BED4-FBD0EAA8CA70

Attachments

Images (2)
  • 2A8A1ADE-A29E-485A-9A36-2DB9A6F80434
  • 7D00C170-EBCB-4F56-BED4-FBD0EAA8CA70

Also, since you are using Atlas switches and I just went through my own ordeal installing and most importantly repairing a bunch of these.

Atlas used multiple rail sections to make their switches. Depending on when it was manufactured, they slightly changed styles and improved over time (IMO).

Early versions used copper solid wires that were spot welded to the rails to connect to the incoming rail. The big thing is, that with very little abuse those spot welds can fail and electrically you would have dead spots in a switch. Since soldering to the solid rails takes a lot of heat, I bought a super capacitor based battery spot welder and used it to weld nickel strips to the bottom sides of rails after cutting away the plastic.

Example topic since I am not the first person to ever see this. The below example is the more modern production and hence the brown jumper wires from the factory. That said, some of those are still to spot welded copper rods or posts to the actual rail sections and I have seen them fail.

https://ogrforum.ogaugerr.com/...ts-in-atlas-switches

Without being there in person to inspect the turnout, my best guess is that the wiring that connects the center rail to the diverging center rails is bad. If you examine the turnout more closely (in the red circle), you will see where the diverging center rail casting is separated from the center rail leading into the turnout. Run a continuity check placing the probes as indicated by the yellow dots. If there is no continuity, turn the turnout over and check the wire for continuity. If you still cannot get a reading, I would replace the wire.

IMG_2772myo54

When I replace the damaged wire on another turnout, I soldered the replacement directly to the rail. Soldering to the side of Atlas black rail is not too difficult. First, you need to prep the rail by sanding away the black coating until you see shiny rail.  The next step is to tin both the rail and wire you are using. Coat the rail with flux to help the solder flow. Remember, the ties are plastic, so me mindful of how long the soldering iron is in contact with the rail.

Hope this helps!

Also, I've had a mixed experience with the Atlas blackened center rail. At club and at home, I ended up using 3M Scotchbrite pads to polish and remove the black oxide finish from the center rail top. I just found that even well cleaned, there were certain engines and pickup rollers that did not like that black oxide and led to sparks and power losses. So again, my experience was we removed the blackening because of electrical pickup issues. YMMV.

3M

This appears correct- only center insulated in how you are using them.

Again, it's not just me, there was a customer who did a massive table locally, and saw the same problem as delivered with blackened rail. It was funny because some rollers worked fine, others sparked like crazy and he was having both power and signal related issues. Then we got into a 2/3 rail MTH 4-4-0 and that was the nail in the coffin on blackened center rail.

Thanks for confirming, Vernon!  I was aware of some issues with Atlas switches which is one of the reasons I dropped as many power feeds as I did.  I read/watched that by dropping the feeds on each leg/side can help with said issues and give smoother operation.  Independently, Both loops work with no issues except when I tied them together as described above with separate power districts.  If I understand, all I need to do next is run the wire to connect the common terminals of the TMCC lock-ons.  Correct?  Again, thank for everyone’s help!  Truly appreciate it!

@LT1Poncho posted:

Just to dig deeper into phasing.... How can you reverse the plug in the outlet when one blade is wider than the other or you have a 3 pronged plug? Is phasing only necessary on older power supplies without these modern plug features?

Phasing applies to any AC transformer when there is more than one transformer. Modern, old, doesn't matter.

https://ogrforum.ogaugerr.com/...-polarization-issues

"How can you reverse the plug in the outlet when one blade is wider than the other?" Easy, break out your grinder, Dremel or file.

"or you have a 3 pronged plug" Then my friend- you have the wrong transformer. Time to rethink those life, I mean train decisions. Your train transformer and our track systems especially with Legacy or TMCC signal must be isolated. So any track or accessory transformer with a ground connector brings out more questions than it answers. The one exception is the small transformer to power a Legacy or TMCC base since it specifically needs the grounded plug for the base to properly create the signal and use your track.

Specific to the Lionel 180 Watt bricks, they sold a plug that would reverse polarity https://ogrforum.ogaugerr.com/...r-for-180-watt-brick

Last edited by Vernon Barry

Karl, it isn't just tying the two grounds together (you do need to do that). You also need to check the phasing. As others have pointed out, after tying the grounds together, put the meter between the center rail of one loop and the center rail of the other loop, it should read 0 or near 0. if it reads like 34v or whatever, the power supplies are out of phase.

I suspect that tying the grounds together will fix the problem, on a more modern power supply like the bricks you are using it is likely they are in phase IME. If they aren't, you will need to reverse the plug on one of them and make sure if you ever have to unplug it you know which way it is plugged in. If you can't reverse it (some plugs are polarized, one prong is wider than the other) you will have to grind down the prong to allow it to be reversed (you also can replace the plug with one with non polarized tabs).

Also, because this was an older topic and won't let me do the quote and copy paste, here we try:

Posted by @Mike CT in this post https://ogrforum.ogaugerr.com/...659#5512461186231659

We had discussed that seperate 120 volt power sources could also cause phasing problems. Home wiring involves an A and B phase.  Transformer one plugged into A phase will not match transformer two plugged into B phase.  Best to plug all transformer into the same circuit.  Commercial wiring involve an A, B and C phase, again best to plug all transformers into the same receptacle/circuit.



Again, this was something I eluded to but did not outright say. It's recommended when doing power to use a power strip and plug multiple transformers into the strip (with a circuit breaker) because you want to source from a single wall outlet of a known phase. Let's say your train room install has multiple outlets on different walls of the room. If you plug one transformer into one outlet and another into the other side of the room outlet- there is a chance they are different AC phases coming in to your house.

Every house and situation is different, transformers are not guaranteed to be in phase even from the same brand and model number. Then heaven forbid your situation uses different outlets

Bottom line again- if you have more than one track or accessory transformer- it's recommended minimally to check phasing of outputs and ENSURE you do not end up with any combined voltage higher than 18V between any 2 terminals. Literally that is the goal- make sure the transformers are not "adding up" because they are out of phase and resulting in a potential where some piece of equipment could see higher than 18V AC.

Last edited by Vernon Barry

Hi, everyone! Thank you so much for all of the great advice!  I am proud (and embarrassed) to say that after much cursing and banging my head, I have resolved the issue.  I did take the advice to confirm that my power bricks were in phase.  I even swapped out the TMCC lock-ons and made sure all of my power feeds were consistent (middle and outside rail connections).  After all of this, my engines were still losing power between a set of switches and as previously stated, I made sure that I had power feeds connected to all legs of the switches.  Vernon pointed out earlier, Altas O switches have been known to have dead spots.  I was prepared for this.  So after all of this, what was the solution and lesson learned?  Double check to make sure you connected ALL OF YOUR POWER FEEDS to your bus wire, lol... SMH.

Phasing applies to any AC transformer when there is more than one transformer. Modern, old, doesn't matter.

https://ogrforum.ogaugerr.com/...-polarization-issues

"How can you reverse the plug in the outlet when one blade is wider than the other?" Easy, break out your grinder, Dremel or file.

"or you have a 3 pronged plug" Then my friend- you have the wrong transformer. Time to rethink those life, I mean train decisions. Your train transformer and our track systems especially with Legacy or TMCC signal must be isolated. So any track or accessory transformer with a ground connector brings out more questions than it answers. The one exception is the small transformer to power a Legacy or TMCC base since it specifically needs the grounded plug for the base to properly create the signal and use your track.

Specific to the Lionel 180 Watt bricks, they sold a plug that would reverse polarity https://ogrforum.ogaugerr.com/...r-for-180-watt-brick

IF there are 3 pronged plugs on transformers out there, as you mention, then it seems silly to rethink life and train decisions. These things exist that's why I asked.

Karl:

I just skimmed through the other posts so am not sure if anyone mentioned this. You said you may add DCS (TIU) to your layout down the road. If this is accurate then remember electrical wiring is different for Legacy vs DCS. A special 'star' wiring scheme is required for DCS. Others can talk to you about this since I don't run DCS. The 'star' wiring will accommodate Legacy however standard 'buss' wiring prevalent for Legacy will not accommodate DCS. You may find out you will have to gut and completely rewire your layout for DCS/Legacy.

@Joe Fauty posted:

Karl:

I just skimmed through the other posts so am not sure if anyone mentioned this. You said you may add DCS (TIU) to your layout down the road. If this is accurate then remember electrical wiring is different for Legacy vs DCS. A special 'star' wiring scheme is required for DCS. Others can talk to you about this since I don't run DCS. The 'star' wiring will accommodate Legacy however standard 'buss' wiring prevalent for Legacy will not accommodate DCS. You may find out you will have to gut and completely rewire your layout for DCS/Legacy.

Sorry but false. We can have another 3 page electrical debate but there are plenty of examples of EITHER wiring scheme supporting EITHER control or both at the same time. I know, our club with a 75x10 foot table with several hundred feet of track was buss wired. Later we added DCS and Legacy and have no issues.

So saying that STAR wiring is a requirement for DCS is not exactly cut in stone.

My modular club uses bus wiring.  Star wiring on a modular layout is not practical.  DCS and Legacy work fine now, but success with DCS was not achieved until we upgraded all modules with separate power AND ground wires for each loop to support signal propagation from each TIU channel.  12G wiring is used to support 100+ ft layout length.  We completely isolate the center and outside rails at crossover switches so the DCS signal from each TIU channel is isolated to a single main line.  The only place where the track commons are connected is at the TIU for the Legacy signal connection.

The star wiring recommended by MTH also provides consistent pairs (power and common) of wires to the track.  Think network cable beefed up to the necessary wire gauge to handle the amperage needed.

If you have a typical post-war layout where the "common ground" bus has track and accessories connected, and ad-hoc connections to power bus wires, (AKA the rat's nest under the table) you are asking for DCS signal issues.

Last edited by Tracker John

Vernon actually it is not flat out false - Barry Broskowitz
"The star wiring method was intended to minimize signal duplication by having all track feeders (and thus control signal paths) as close to being the same length as possible.]

This myth still comes up every now and then though it was proven years ago  that the wires being equal or unequal have no effect on DCS. But having more than 1 track feed per block can cause signal duplications"

"Star wiring, with center rail-insulated blocks, is implemented primarily to ensure that a DCS engine (PS2/PS3) sees only one incidence of a command, rather than multiple incidences separated in (not very much) time.

Regardless, DCS is considerably more tolerant than one would suspect and, consequently, some different wiring schemes will yield acceptable, if not perfect, results. When adding DCS to an existing layout, the best advice is to just hook it up, see what you get and work from there.

https://ogrforum.ogaugerr.com/...-do-buss-wiring?nc=1

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