A couple months ago I posted my thoughts on the electrical circuit needed to get safe power from the transformer to the tracks. After some great input by Dale H, HOSO&NZ, and Dale M, this was the finished diagram:
PH180 – TIU (Rev L) – terminal block – TVS 30V 1500W – track – car/engine rollers – 22uh 0.5 amp choke – TMCC board/other DCS signal killers
Shortly after this, I read about the passive TIU mode where track power did not go through the TIU. This interested me because I have a fairly long mainline in my new track plan where I can run multiple long passenger trains. I now think a TPC400 with 20 amps would meet my needs better than the 10 amp limit on the TIU, and I understand the arc welding concern expressed by some when using the TPC with two PH180s. I don’t need the TPC for conventional control, I’m just using it for the higher amps. My new power circuit looks like this:
TPC400 (powered by two PH180) – terminal block – TVS 36V 1500W – track – car/engine rollers – 22uh 0.5 amp choke – TMCC board/other DCS signal killers. The TIU (Rev L) would be connected between the TPC and the terminal block (with the TIU red post connected to the TPC post A, black to U).
My questions are 1) what wire size should I use and 2) will the 36V TVS be adequate for this new circuit? Any other comments would also be appreciated.
Thanks.
Ron