First DCS Layout - Couple of (I think) Easy Questions

I can address #2 and #3.  I use K-line O27 42" switches and also use DCS.  I, like you plan on doing, do not use track power for the switches - I too use external power.

To compare us, I use an MRC dual 270 thru a TIU to power the tracks and use a Lionel 'ZW' for the switches.  Yes, you HAVE to phase them.  My memory is not crystal clear on this but I think you have to connect the grounds of the 2 trannies too but I'm not 100% sure about that.  Easy to test though. 

When I'm setting up the layout for Christmas I test the switches even before I connect track power, which sounds similar to answering one of your questions.

- walt

@walt rapp posted:

I can address #2 and #3.  I use K-line O27 42" switches and also use DCS.  I, like you plan on doing, do not use track power for the switches - I too use external power.

To compare us, I use an MRC dual 270 thru a TIU to power the tracks and use a Lionel 'ZW' for the switches.  Yes, you HAVE to phase them.  My memory is not crystal clear on this but I think you have to connect the grounds of the 2 trannies too but I'm not 100% sure about that.  Easy to test though.

When I'm setting up the layout for Christmas I test the switches even before I connect track power, which sounds similar to answering one of your questions.

- walt

Thanks Walt. That's good and useful feedback for me. I remember your prior posts about the K-line 42" O27 switches.

I'm running 4 separate PW transformers through the TIU.  Two LWs and two RWs.  Gets me plenty of power and, since they're below the train table, not in my way.  I just happen to have a plethora of single throttle PW transformers.  I keep my ZW (bought refurbished about 5 years ago) for the Christmas layout since it takes up less floor space.

Are you using fast-blow fuses and TVSs? I bought plenty of each. Planning to insert the fuses between each transformer's hot and the TIU. Is that right?

Then planning to put the TVS across the various lock-ons OR across the hot/common on the transformers if the leads are long enough. Any other places you'd recommend placing the TVSs?

There may be other ways to do it, but my thought as to #1 is to use the fixed terminal for the mainline on which you will only run command control exclusively and never conventional. For the mainline on which you will run both, I would use the variable channel output - that way you can select a higher voltage (18v, e.g.) from the remote when you run command and a lower voltage when you run conventional.

If you are using terminal blocks like these, you can also put a TVS across the inputs.

For the past dozen years or so... on the ZW I put the 4 TVS(s) on the transformer and a second set of 4 TVS(s) @ the block terminal (as Ritchie noted above)...  I use 4, 7 amp breakers (manual reset) from digi-key.   Others may digress... but, I have never blown a board.   I use my RW on the test station with a 2 amp breaker... works Great!

@Richie C. posted:

There may be other ways to do it, but my thought as to #1 is to use the fixed terminal for the mainline on which you will only run command control exclusively and never conventional. For the mainline on which you will run both, I would use the variable channel output - that way you can select a higher voltage (18v, e.g.) from the remote when you run command and a lower voltage when you run conventional.

If you are using terminal blocks like these, you can also put a TVS across the inputs.

Thanks!  Yes, I am using the MTH terminal blocks. Great idea putting them here so they're not visible as they'd be on the lock-ons.

@raising4daughters posted:

Thanks Walt. That's good and useful feedback for me. I remember your prior posts about the K-line 42" O27 switches.

I'm running 4 separate PW transformers through the TIU.  Two LWs and two RWs.  Gets me plenty of power and, since they're below the train table, not in my way.  I just happen to have a plethora of single throttle PW transformers.  I keep my ZW (bought refurbished about 5 years ago) for the Christmas layout since it takes up less floor space.

Are you using fast-blow fuses and TVSs? I bought plenty of each. Planning to insert the fuses between each transformer's hot and the TIU. Is that right?

Then planning to put the TVS across the various lock-ons OR across the hot/common on the transformers if the leads are long enough. Any other places you'd recommend placing the TVSs?

Yes, I use fast blow fuses.  Don't remember the specs on them though since they are currently put away.

You are correct - put one between the trannie and the TIU, hot.  And like you want to do, I also put one on every lockon, which with DCS and blocking, means A LOT!  And since I use star wiring with DCS I also put one on each terminal block.

If I had the soldering skills and electrical know how, I would do what the 'experts' say and put one INSIDE each engine.

=- walt