My brick keeps tripping.

If you really are running two trains on one 75 watt brick, yes, you are exceeding the output.  There is some overhead used by the TIU as well as the draw of the trains.

Is there a way to add more power?

The simple answer to add more "power" is to upgrade to a larger transformer.  Both MTH and Lionel make several nice transformers.

I have one of my power districts that is powered by a z750 and always run three trains and never blow circuit breaker on the brick...  I'll try four trains and see if there's an issue.

However, It will blow the breaker if the voltage isn't high enough.  I usually power all power districts up to 18v.  If its lower it will trip the breaker especially with lighted passenger car trains.

Must be pretty small consists, I can't imagine running three decent sized configurations on a 75W brick!  On our modular layout, we run into problems with three consists on a loop if one is a lighted passenger train, and we're using 180W bricks!

OK thanks everyone. I am running a U.P. Big Boy with 4 lighted pass. cars and a PA AA with 6 light pass. cars. I'll try the Z-1000 or just run one passenger train with a freight train.

Theres your answer. Lighted passenger cars are a big power draw. That transformer would be marginal to run one of those passenger sets let alone two of them.

sounds like it's time to ungrade to LED's.

Yes. it's small but decent to me, imagine toy trains   Tonight I tried four trains on the z750 and it was fine,  Didn't run the smoke though to see if that would trip it (I'll do that tomorrow when wife is out and about).  Actually one of those engines doesn't have smoke but has passenger cars.

The engines are GP38, 060, 080, and F59 that are running the upper mountain z750 district.  Here is a link to some pictures I took tonight with all 4 running.  http://s356.photobucket.com/al...?albumview=slideshow 

(and a poor quality video) 

http://s356.photobucket.com/albums/oo3/litegide2424/MTH%202013/?action=view&current=DSC_0106.mp4 

All of those are running on one 75 watt transformer?  Color me amazed!

I have 4 750 bricks, can you bridge say the 1 fixed and 1 variable on the output side to get more power to the track?

NO!  You can power multiple channels on the input side, but it's a really BAD idea to jumper the outputs together!  You need larger input transformers, you can supply up to 180 watts to each channel.  You can get away with paralleling identical bricks on the input side, so you could parallel two of the 75W bricks and get 150 watts input to one channel.

Can you check your current draw? If so (or if not)I'd try running without the passenger cars and add them 1 or a few at a time and watch. If you find it is the cars, I think there must be affordable LED bulbs, that will give the same effect as the incandescents in there now. Just a thought. If there are not inexpensive bulbs, by the time you upgrade 10 passenger cars (even at $10 each), you might want to sell all your transformers and go for a z4000 or something.

Its really hard to believe that that layout is powered by one 75 watt transformer.

Good Morning, guys:

I hate to sound like a broken record, but here is the advice from an old electrician:

Moving wires around, coupling outputs, running more and more trains until something releases its smoke, are all called "empirical" testing, or among the professionals, "quite silly."

The answer to lots of these problems is just simple mathematics. Yes, math CAN be simple. Every load, such as a motor, lamp, coil, draws a certain amount of current. Current is measured in amperes.  Just add up all the amps, or fractions of amps, and then look at the maximum current that a power supply can provide, and you have the answer. 

A meter will tell you the current draw of a typical motor or lamp. Then just add 'em up. If your load exceeds your supply, get a bigger supply, or reduce the load. One method that others have suggested is changing incandescent lamps to LED's. LED's use a mere fraction of the juice that tungsten lamps use. That's the first step.

John- thanks, not sure why I didn't think of that. Just to clairify a few things, I'm not powering my entire layout with 1 brick. I built this before DCS as 3 main line districts and all the different sidings, yards and turntable area. I started with 80w Lionels, then switched to the 750's with the controllers after I bought a MTH RTR set. That's when I heard about DCS and how you can run multiple units on one track independent of each other - run your trains not the track. I was just curious why I saw Utube videos with 5 or 6 powered units on one consist and I couldn't get two to run at once, I never took into acount the light in the passenger cars as a big draw and I didn't think of parralling two bricks on one input till John brought it up. I love this site, lots of good information.

Some folks will tell you that paralleling bricks is a bad idea, but if they're identical bricks, it works fine.  Lionel even recommends it for connections to the TPC300 and TPC400, and they're using higher power bricks!

I'll be the first to say it's not the "ideal" situation, but it will work fine and you'll get twice the power on the one TIU channel.

I paralled 2 Z-750's on both fixed 1 and fixed 2, running 2 trains on each track and everything seems fine. So just a question, have you ever paralled a 750 and a 1000? just asking.

I've never used the MTH bricks like that, just single ones.  I actually don't have any of them now, just Lionel 180 and 135 ones.

 If I put two of the same bricks in on each channel (with a correct size fused hot lead on each??), would the TIU be protected??

I don't know Joe about 2 fuses. Maybe parallel the transformers first and have a single lead  with the fuse to the tiu input.  I usually get these things backwards but wouldn't 2 fuses  in parallel  double the amperage flow?

I'd probably want to keep the total current capability of the two transformers below 10-12 amps.  I'd personally use one fuse after the two were paralleled, the MTH bricks have a circuit breaker to protect the brick.

Just a s an FYI...

If anyone were to connect two transformers to the same connected tracks through two different TIU channels, they could be looking at two very real possibilities.

One could be a severely degraded DCS signal. The other could be a fire or other damage to electronics.

We're not talking about connecting two tiu channels together. Paralling to transformers before to tiu. I want to keep the MTH units and not have to switch 180watt Lionels, if the tiu will handle 180 watts per channel then why not run two z-750's or a 750 and 1000 is the question now. As far as the fuses, the tiu is fuse internally and the bricks have breakers so I don't see a problem there.

if the tiu will handle 180 watts per channel then why not run two z-750's or a 750 and 1000 is the question now

Because yiou cannot just connect two power sources that are not exactly matched in terms of voltage without having a difference of potential, aka voltage, generated. That voltage can cause a fire.

That's one of the reasons why TPCs were invented. To combine transformers.

would the tpc be useful then  to get more amps from two identical bricks into a single channel (before the TIU)?

Joe,

would the tpc be useful then  to get more amps from two identical bricks into a single channel (before the TIU)?

Absolutely! If you want to exceed 10 amps/channel, however, connect the TIU in Passive TIU mode.

 for some reason I kept thinking I could run them to 15 amps??

For a very short period only, then you get to send it to MTH for repairs.