I'm not an electrical genius, but am wondering why are the TIU output ground terminals internally isolated from one another, when they become common grounds with the outboard rails of the track?
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I suppose some like to run different scales ( HO) (2 rail AC) or large scale that could be controlled from the same TIU and dcs remote.. Of course you would now need completely separately loops powered by a separate channel for the other scales... Something like that.. 
Thanks Gregg, sounds logical to me.
Barry would you like to comment on this?
Barry would you like to comment on this?
The original, Rev. G, had the Commons all connected. That changed when the Rev. H was released.quote:Barry would you like to comment on this?
I can't say for sure why that was done, however, I expect isolating the Commons was, as Gregg commented, to allow more flexible train operation.
Aren't the commons on the Rev. L TIU tied together? I have a Rev. L running legacy and only have one wire running to fixed one common output and get legacy signal to my isolated line on fixed two...
No, they are not.quote:Aren't the commons on the Rev. L TIU tied together?
Be aware that the Legacy (and TMCC) signals are RF. They will easily jump across insulated track joins, whether they are insulated by air gaps or non-conducting track pins.
Thanks for the reply's guys.
Since I also run TMCC I figured that even though the Tiu grounds are isolated the track ground rails are not, so 1 signal wire will still work as usual.
Since I also run TMCC I figured that even though the Tiu grounds are isolated the track ground rails are not, so 1 signal wire will still work as usual.
If all the commons are tied together and you have a multi-output short, then the common wiring connecting all the commons within the TIU would need to be able to handle the combined current without overheating and starting a fire.
The place where this can happen on the layout is on the common buss bar that connects all the blocks. My common buss bar could easily handle 40 amps, so this isn't a problem.
However, the internals of the TIU might not be able to handle this.
Maybe... I am not an electrical engineer and I'm just guessing.
Mike
The place where this can happen on the layout is on the common buss bar that connects all the blocks. My common buss bar could easily handle 40 amps, so this isn't a problem.
However, the internals of the TIU might not be able to handle this.
Maybe... I am not an electrical engineer and I'm just guessing.
Mike
My layout is basically divided in 2 parts using the right and left throttles of my Z-4000 with 2 insulated loops. I've had this setup since DCS first came out with no problems. I alway match both thottles to the same voltage before running
my trains. I feel that between my Rev L TIU fuses, and my Z-4000 breakers I'm protected pretty well.
my trains. I feel that between my Rev L TIU fuses, and my Z-4000 breakers I'm protected pretty well.
