Alternate use of DCS TIU Passive wiring:
To simplify DCS wiring the DCS TIU can be wired in "Passive Mode". As a result 18vac power to the track is wired directly to each block entirely bypassing the TIU input. (No input connections to the TIU are required).
This system applies track voltage using separate 12vdc relays which are operated via the TIU/AIU system. Wiring to the track is protected by separate circuit breakers for EACH block circuit output connection. As a result a short circuit in any block connection is individually protected so that a loss of power to the other blocks is not affected. Wiring to each block uses 16 gauge wire.
DCS signal wiring: All wiring from the TIU Output to each block uses 22 gauge wire. The TIU outputs bypass the block relay circuit entirely and are permanently wired to the center rail. Each wire to a block from the TIU includes a series connected 560 ohm isolating resistor.
Note: The maximum current in the wiring from the track to the TIU is 40 miiliamperes so no fuses are necessary to protect the TIU output when using the TIU Passive control wiring scheme.
The circuit breaker panel shown includes an individual resettable circuit breaker for each block circuit output.
