Make the Variable Voltage output work like a fixed voltage output

Set Variable channel to Fixed channel:

MENU/SYSTEM/DCS SETUP/scroll to VARIABLE 1/FXD softkey

MENU/SYSTEM/DCS SETUP/scroll to VARIABLE 2/FXD softkey

Thanks, Gary - just what I wanted.  I am using Lionel 180 W power bricks (only the bricks, no ZW).  I have all four bricks turned on and off by a common wall switch; I notice that when I turn on the wall switch, the breakers trip on the bricks feeding the variable inputs (now fixed), the two feeding the original fixed inputs are fine.  I can reset the two tripped bricks immediately and everything runs fine - any ideas?  Thanks, Var

Var;

Perhaps you didn't notice, the Banana plugs are also screw terminals, and yes, they are big.

I just thread the wire into the hole in the terminal and screw the plug down on it. It makes a very secure connection. And you can get spade lugs that big but I don't find it necessary.

As to the breaker popping, How much current does that track draw?

It's possible the startup surge on all the engines is too high.

Thanks, Russell.  I did notice the holes in the binding posts; I prefer to use connectors across the board (ideally, crimp connectors).  Just seemed kinda stupid but that's just me. 

Re the current:  I can repeatedly turn the bricks on and off without the breaker popping after the first event - almost seems like something is charging up, however, if it was capacitive charging, that would not create a current spike.  I can reset the breakers and all is well; just bothers me that this happens at all.  Any other speculation would definitely be appreciated - I would like to run this down and fix it

What are you using to power the TIU?  If you're using Aux Pwr, is that source turned on first?  If you're not using Aux Pwr try turning on the brick that feeds FXD1 first and then the other three.

I am using one of the bricks to power the TIU; I turned off all but that one, then turned on the remaining three bricks and again the two connected to the "vaiable output" tripped.  I turned everything off with the wall switch and then back on again; I waited ~ 15 seconds and an odd thing happened:  one of the two "tripping bricks" made a sound like the breaker tripping and then a few seconds later, a similar sound and came on by itself - this is reproducible.  Very strange   Just out of curiosity:  when engines are parked on a line powered by a brick, how much current do they draw when not being set in motion?  I am starting to believe that Russell may be right about too large a draw (I don't have an amp meter to measure the draw and anyway, that would not yield a number for the transient draw).  Any thoughts?

Are you sure that all the bricks are properly phased?  Only way to be sure is to test all---can't rely on polarized plugs.

Yes, I checked that before this started - thanks for the suggestion!!!

You say you are using one of the bricks to power the TIU.  But you don't say if that is through the AUX port or merely by using FIXED 1.  If the former, the polarity going to the plug in the TIU AUX port is important.  If you feed through the AUX port using a wall wart, polarity isn't important and AC or DC can be used.

Just wondering, did you try swaping the bricks from variable input to fixed input ports, and if so did the same bricks trip or did the tripping stay with the variable ports.

Yes, I did that as part of my original troubleshooting - no joy

Var,

Can you try to switch the outputs on the TIU, unplug fixed 1 out and var 1 out and swap them.

That should tell you of the load on the track that each of those feeds is the issue.

My setup is like this:

Small MTH accessory transformer powers the TIU with the TIU AUX Power jack (Not Fixed 1)

Then I have 4 Lionel 180 watt bricks each feeding into the four tiu inputs.

Everything is switched off a power strip.

I have the accessory power for the TIU comes on as soon as the power strip (Master) power goes on.

Then I individually turn on each 180 Brick.

I do that because I want to make sure the TIU is fully powered up before I send any voltage to the tracks.  

Another advantage is a short on track fixed 1 can just be reset at the brick without killing the whole layout (e.g. the whole TIU...)

I can easily emulate your setup by pulling the accessory voltage to the TIU and leaving all for 180 bricks on with the master.   I will try that and post back what I see.  Probably tomorrow.

I did as you suggest and the problem reversed, however, the power bricks behaved very strangely (i.e., giving an audible click ~ 5 seconds after powering up and only then permitting reset).  What is the load of the TIU; also, can you estimate the load of an engine sitting at rest?  Thanks!!!

I tried my setup as you describe but go not reset on the bricks.

How many engines are powering up on that track at start up?

Sorry for the delay in responding - out for surgery   I have 4-5 engines on the track; what puzzles me is that the brick easily resets after being tripped - shouldn't the load be constant (particularly since they are standing still)?  Thanks, Var

There could be an initial power-on surge that is tripping the breaker.  Have you tried taking the locomotives off the track one at a time to see if one particular one is causing the issue?

No, good suggestion - it will have to wait until my knee is healed, but definitely will be done.  Thanks, Var

Another idea.  Did you swap the track connections between the variable and fixed inputs?

Yes, the details are ~ 5 posts above (comments welcome).  Thanks, Var