How to hook up a DCS TIU to a Lionel Legacy and a Lionel ZWL for the power

No, and it's not your fault, I remember first getting into this hobby and nearly making the same mistake with variable terminology.

The fixed channels of the TIU just pass whatever comes in on the input to the output and adds the DCS signal. You can feed them with either fixed voltage (example 180W Powerhouse) or variable voltage from another transformer like a Z4000, ZW, ZW-L and so on.

The variable channels of the TIU can manipulate the output voltage. Ideally you feed them (input) with a fixed voltage and the TIU variable channel varies the output.

The catch22- the TIU is an electronic device and needs it's own power to run the electronics inside it. They gave 2 ways to power this. One way is the Fixed Channel 1 input of the TIU can borrow some of that power and power the TIU logic. The problem with that is, then TIU fixed input 1 must ALWAYS have power. If you are feeding that from a variable channel of another transformer and say for whatever reason you ONLY want to power the second track (fixed input2) it won't work right because the TIU logic isn't powered at the moment. So they also gave you AUX input power on the TIU that accepts AC or DC 12-18V from a typical wall power adapter. I highly recommend going with the aux power route.

@CAPPilot made some posts long ago and I slightly edited some of his posted diagrams.

Even though this says Z4000, a ZW-L or other multiple channel transformer would be the same. Also note, I believe in secondary external protection for a typical TIU (given the insane cost of them these days and supply and demand). Yes, the later TIU revisions have built in fuses, however they are 20A from the factory and absolute last resort. I would suggest a lower fuse rating externally (typically 7.5-15A would be appropriate IMO) that is easily replaceable VS having to open the TIU for a blown fuse. Edit- again my personal feeling is the fuses in the TIU are just there as an absolute last resort, they are very high rated 20A fuses that should not blow under normal circumstances and I do not believe in depending on them to protect the TIU against damage- let alone anything like your trains, track or wiring. The reason why I would specify and place a fuse in between the power source (transformer) and the input to the TIU is that the TIU also contains TVS diodes on the output. Often when voltage spikes caused during shorts and derailments eventually blows one of those TVS diodes, they short out. That short then makes all the electronics and traces inside the TIU a connection between a dead short on the output and your transformer. The fuse is thus placed before the input to account for this known failure condition or state.

Again, just to get technical. What to avoid is sending a variable output of especially an electronic transformer like a ZW-L that is chopping up and changing the AC voltage, and then feeding that into another device like a TIU variable channel that again tries to chop up and manipulate the output voltage.

This double manipulation (because chopping probably isn't the correct wording if honest) leads to a pretty ugly output.

Hi Vernon,

Thanks so much for the great reply and the terrific instructions and wiring diagram for setting that up.  what I thought would work was totally off base, I would have probably blown everything up and been out a load of money and then I would have been a very unhappy camper to say the least.

Would you mind if I contacted you via your email address, I have a couple of questions I want to ask you and see if you agree or not.  If you would rather I didn't and just kept it on the forum, I will fully understand.  Or, if you would like to contact me via my email address, it is sptrainnut@att.net, that would be totally fine with me also.

Thanks again for you great post and diagram, it really gave me a good idea as to how it needs to be done.

Have a wonderful rest of the week and a great weekend.
Cheers,

I prefer to keep on the forum because of the hope the answers and questions may help others. If I do it in email- then nobody else benefits.

Sounds good, fully understand so here goes:
1)  I have the Lionel 6-22983 180-Watt Powerhouse Power Supply, can I cut the plastic molded plug that is meant to plug into the PowerMaster unit, and find a plug that will plug into the Aux Power Unit on the end of the TIU.  Will this suffice as enough power for the TIU or is it to much power for the TIU?

2)  Does MTH make a separate power supply strictly for the TIU, then I could get one of those and use it instead of butchering the Lionel PWR Supply?

3)  I don't remember where I heard or possibly read this but someone had suggested that you put fuses between the "outputs from the TIU" so that they will trip before the fault gets to the TIU.  Also what value would you recommend for the fuses between the ZWL and the TIU F1 and F2 inputs?

4)  If I'm reading the schematic correctly, the wire on the Legacy Command Base U Post will now be spliced into the "hot leg/middle rail" wire before going to the two terminal blocks and then up to the middle rail of each set of tracks, in my case the inside line and the outside line.  Is this correct.

Thanks so much for your help and I really look forward to your answers to my questions.  The hardest part now will be finding a small plug that goes into the TIU that I can splice together with the power cord from the Powerhouse Power Supply.

Have a good evening.

J Motts

@J. Motts posted:

Sounds good, fully understand so here goes:
1)  I have the Lionel 6-22983 180-Watt Powerhouse Power Supply, can I cut the plastic molded plug that is meant to plug into the PowerMaster unit, and find a plug that will plug into the Aux Power Unit on the end of the TIU.  Will this suffice as enough power for the TIU or is it to much power for the TIU? Way overkill!!! It's not that it's too much power, it's that those are pretty valuable right now, I wouldn't go chopping the plug off to use it to power a TIU when a suitable 12-18V AC or DC adapters are a dime a dozen. Heck if you have an old wireless router, it probably has a 12V power adapter.

2)  Does MTH make a separate power supply strictly for the TIU, then I could get one of those and use it instead of butchering the Lionel PWR Supply? Yes, MTH sold one, but not worth chasing that exact one and they were overpriced. Google this or any 12V 2A adapter with the coaxial common plug Chanzon 12V 2A UL Listed 24W AC DC Switching Power Supply Adapter (Input 100-240V, Output 12 Volt 2 Amp) Wall Wart Transformer Charger for DC12V CCTV Camera LED Strip Light (6Ft Cord, 24 Watt Max)

3)  I don't remember where I heard or possibly read this but someone had suggested that you put fuses between the "outputs from the TIU" so that they will trip before the fault gets to the TIU.  Also what value would you recommend for the fuses between the ZWL and the TIU F1 and F2 inputs? While you can put fuses on the output- my recommendation is BEFORE the TIU input because again, your intent is to protect the expensive TIU. The TIU is not the source of the power- the transformer is. That power then flows through the TIU to the output. If the TIU internal TVS diode fails, it shorts the output of the TIU. That means it shorts through the tiu and the internal components are all seeing that dead short current. Again, it should be common sense- put the fuse or circuit breaker at the SOURCE- your transformer. You put current protection (fuse/circuit breaker) at the source, you put voltage protection (TVS) nearest the load.

4)  If I'm reading the schematic correctly, the wire on the Legacy Command Base U Post will now be spliced into the "hot leg/middle rail" wire before going to the two terminal blocks and then up to the middle rail of each set of tracks, in my case the inside line and the outside line.  Is this correct. No, you are not reading correctly, TMCC/Legacy signal is to the outside rail or black TIU terminals, or "U" of the transformer.

Thanks so much for your help and I really look forward to your answers to my questions.  The hardest part now will be finding a small plug that goes into the TIU that I can splice together with the power cord from the Powerhouse Power Supply.

Have a good evening.

J Motts

No dot = no connection. Conversely dot = connection. The Legacy base wire is going to the black terminal which would also correspond to outside rail of 3 rail track.

Also, that detail is important for another reason.

The TIU terminals, even though this is AC power, they are polarized red and black. Red must to to center rail, and black must go to outside rails. This is because PS2 engines are polarity sensitive. If you miswire the track to the TIU, then a PS2 engine will not see the DCS signal and will not be able to add to a remote or app and will not run under DCS.

PS3 engines are improved and no longer polarity sensitive but PS2 is. That's why getting the track wiring right for both DCS and TMCC is important.

TMCC- outside rail

DCS- TIU output black to outside rail, red to center rail.

Thanks so much Vernon, I really appreciate you taking the time to help me and set me straight.  I will look for a 12 volt transformer like you suggested that I can plug in to the TIU.  One last question though, on the two circuit breakers going from the ZWL to the TIU, what do you think is a good value for the circuit breaker, 10 - 12 Amps or lower?

Thanks again, I'll gather my parts and get after it.   Have a good evening.

J

A lot of people, including me use 10A.  Never had an issue.

Ken

@J. Motts posted:

Thanks so much Vernon, I really appreciate you taking the time to help me and set me straight.  I will look for a 12 volt transformer like you suggested that I can plug in to the TIU.  One last question though, on the two circuit breakers going from the ZWL to the TIU, what do you think is a good value for the circuit breaker, 10 - 12 Amps or lower?

Thanks again, I'll gather my parts and get after it.   Have a good evening.

J

Personally I would say lower. It's up to you and what you run. In theory the ZW-L has some form of short circuit protection. How and when that kicks in and short VS heavy load, how long it waits before kicking in and so forth.

My own personal home layout has 5A thermal breakers. Keep in mind, I only have 10x14 room at the moment, most of my passenger fleet is 5-7 cars at most and LED lighting, and even when I play around and dual head a train, I'm under the 5A. I use something that low because my layout also gets double duty for repair testing. With the typical low end Lionchief and other stuff I see, the wiring in those is pathetic and will vaporize with a short and a higher amperage breaker or fuse.

In general, it's recommended to use faster magnetic/hydraulic breakers (Airpax) or other equivalent. As for rating, it depends on what you expect to run but again, in my experience, at home I run 5A, at club we use 7.5A (and that's a massive 75foot long by 8-10 foot deep layout) and I've yet to see someone overload running a train. Sure, they derail something and short it and it trips, but again, real world running trains, 7.5A per track has worked thus far.

I intend one day to install some PSX-AC electronic breakers, but the problem I'm chasing is since I also need to run conventional on occasion, they don't turn on until the logic reaches a certain voltage. This kind of makes a jumpy start for conventional. If you run command (and thus a constant 18V on the track), they are great and one of the better choices IMO.

Vernon, I was originally thinking about 5A breakers but thought that might be overkill, I was wrong, that's what I will use.   My layout is only 12'X10' and is just the two loops.

One more question and I will stop pestering you, I have an old HP laptop power supply, do you think that would work?  It says it put out 18.5 volts, not sure if that is way too much for the TIU or not, its just a thought.

Ken, thanks for your reply, it is much appreciated.

You guys have a great day, have to take my 96 year old mom to the eye doctor today so she can get her shot in the eye but when I get back I will check back to see what you think about the mentioned PS.

Cheers,

The HP power supply will work fine to power the TIU.

Hi John, thanks for the reply, after my post this morning, I took the plug and tried to get it to go in but the TIU tip in the hole was too big and I couldn't get the plug to go into the port.  So, I ordered a 12V wall wart so hopefully that will work.  I'll let everyone know in a couple of days.

Cheers,

That surprises me a little, the power connector on the TIU is a 2.1/5.5mm barrel connector, by far the most common type.

John, the PC is an OLD HP, I had a new hard drive put in it in 2017, as the old one crashed.  It has Windows 7 as the operating system on it.  I keep my Legacy base list on it for my locomotives. I tried the power cord again on the TIU and I'm trying to get it into the Aux Power Input port on the TIU but it will not go in because the wire that you see sticking out thru the middle is too large for the hole on the plug.  Maybe its because of the plastic insulated tip (yellow), I don't really know but possibly the age might have something to do with it.  Also, I just noticed that the hole in the yellow tip is elongated and not exactly round, maybe that has something to do with it.  It slips in smoothly on the PC but doesn't want to budge on the TIU.

That connector is is a little too new for the TIU. Most laptop power supply's abandoned the standard 5.5mm barrel connector over a decade ago.

You can just lop that connector off and put a 2.1/5.5mm barrel connector on it, positive to the center pin.

I can't do that, it runs that PC because the battery doesn't really hold a charge for very long because of the age of the computer.  I think I bought that computer around 2011 or 2012 and used it until the HD crapped out.  I've never used it since until last weekend when we set it up for the Legacy Base stuff.  I only use it strictly for the Legacy base and use only the Legacy wifi, it doesn't get to go on the big internet.  If I decide to buy a new Windows LT, then I'll use that old PS and put a new plug on the end like you are suggesting.

Thanks so much for your all's help, I'll report back when I get things going again.

Cheers,

That's different! I have a box of old laptop bricks, I figured you had one from a dead laptop, not one you were using!

Good Afternoon Guys,

I just wanted to thank everyone who answered my questions and made so many great suggestions, I  want to report back to you all, that I was able to get everything wired up and now I'm able to run both DCS, Legacy, TMCC and Conventional on my up in the clouds layout.  I was sooo happy when I put one of my MTH Proto 3 engines up top and I had to think about how to get it started but once I did, it ran like a champ.  Then I put a Legacy engine up there and ran it too, everything checked out and I had both running at the same time.  I then went to work to clean up all the wiring and get it all in shape and all is nice and neat.  I plugged everything into an 8 outlet surge protector with a Master Switch so that it kills everything or turns on everything at the same time, except my ZWL, I always turn it off before shutting the rest down and I turn it on last after I turn the Master on, just my quirk I guess, I'm sure everything will be ok but I just don't want to take any chances with it.  That sucker was as bad as buying a brand new engine.

My 4 almost 5 year old grand daughter likes to run my Thomas The Tank Engine set and that is the first thing she asks to do when she walks in the house.  Guess I have a new engineer .  She even runs it at a nice slow pace and not like a race horse.  I set the rules when she started to run for the first time and she hasn't done anything different.

Now it's time to start on some scenery and build some structures and put some clouds up in the sky, maybe even some shallow hills and mountains.  Even though it is up in the air, it needs all that for when you take some pictures or videos.

Thank you all again, it is so much appreciated.  Have a wonderful weekend.