Electrical districts

Power districts are a good idea.  However, you might want the ZW's in one place in case you have to move handles.  I keep all my transformers on an old TV cart. 

George

You can minimize voltage drop with proper wiring. No need for power districts except for signal issues IMO.

A problem with using 2 or more transformers on a loop is that the pickup rollers bridge and isolated center rail,paralleling the 2 transformers. When this occurs the potential of both transformers are on the loop,this could cause excessive arcing in a short circuit. 2 PWZWs could put out 20 amps or more.

The breakers on the old ZWs are very slow. I add external ones,shown here or fuses

LINK

The TIU has a TVS in it but I would still add more as shown.

Dale H

Thanks guys!

  Food for thought.  Looks like grouping them together, rather than spread out makes better sense.  Just compensate for power loss with heftier wiring.

Bruce

Just a question but 3 ZW's seem like a hefty bit of power.  What size layout do you have and what do you plan on powering?  

I'm planning to fill a 400 sq. ft. "T" shaped room.   Power line lengths might top 20' or more.   As much mainline as possible centered around a suburban passenger and freight yard.  Hopefully there's room for a conservative sized engine facility too.  A hidden staging yard location has already been roughed in.

Bruce 

Since you were going to put the transformers in different locations, I assume that you were going to use them at a pre set voltage?  If so, most of your problems will be resolved if the transformers are properly phased and adjusted so the voltage measured across the center rail insulators is zero.  On a ZW I always use an external circuit breaker and do not depend on the internal protection proved by Lionel.  I think Dale's web site has information on this. 

I use a single MRC 270 watt transformer with power runs in excess of 35 feet with no measurable loss.  14 g feeder wires.  The thing doesn't even get warm.  Rich Battista of the Black Diamond RR (on the forum, he has great videos) uses a single MTH Z-4000 (400 watts) to power a massive layout.  That was why I thought the 3 ZW's were excessive.  I suppose it also depends on what you are running.  Modern stuff seems to draw a whole lot less power.  

David,

  The plan is to utilize both Legacy and DCS so the intention was to power all track feeds at a constant 18V.  Dale's concern about arcing has me rethinking that plan and instead just designate one ZW for track power.  Keeping it simple should definitely help with wiring and avoid signal issues. 

Necrails,

  I'm sure we agree that what I'm building would never be called massive, so probably using 3 ZW's is a bit of overkill.  It's your feedback that helps me determine what is best suited, since I've never built a layout this big before.  My conventional engines would cause the biggest draw but then I can only use them one at a time anyways.  It seems best to just use the extra ZW's to power accessories, switches and lighting.

Thank you all for the helpful input.  Since I'm quite a ways away from powering up anything, I'll keep your advise for future use when wiring begins.  Just to reassure all, I'll definitely place circuit breakers inline to help avoid smoke of the unwanted kind.

Bruce