Postwar ZW ok with electronics?

Postwar ZW,  That's what I am running. Though I have additional 8 amp breakers on each throttle/block along with TVS diodes. 8 amps per throttle allows 144 watts per  @18V.  I  run AA Alco PAs with 4 motors plus 8 lighted passenger cars and never trip the 8A breakers though I have tripped the 6A polyfuses  installed on the lead loco DCRU output to the motors.  I intend to make copper heat sink fins for that DCRU as copper dissipates heat much better than the aluminum. IMHO if proper precautions are taken the postwar ZWs work fine.

Any ideas on part numbers for the TVS and where to get the fuses / Breakers?  Was thinking of going through Mouser, or Digikey.  I believe the TVS need to be bipolar.  I've looked on their sites and can't decipher which ones to get.  Also. I assume if there are bipolar, they can be hooked up in either direction? Or is there a common/ negative side that needs to go to the U post?

Also any suggestions on inline fuses/ Breakers?  8 Amp seems a little large. I was thinking more along the line of 3 - 5 amp ?

I'll be running the TVS, from the positive binding post of each throttle to the common, and the fuse or circuit breaker off the positive side of each throttle, inline to the center rail.  I assume that's correct?

Any help would be greatly appreciated. The CW 80's are a little wimpy sometimes.

Even though you are only running LionChief, I would not go lower than 5 amps so you can run several lighted passenger cars and maybe even double head/MU your engines if they are the same type model.  Because there is a TVS failure that is not detectable, I like to have at least two between my engine and the transformer.  I would put one TVS across the posts of the ZW, and another one at each track connection (see diagram). The TVS recommended here on the forum is a 1.5KE36Ca (sometimes written as 1500KE36Ca).  Several folks here use auto fuses; just make sure they are accessible.

Rule of thumb: modern equipment, modern power source. It only takes one smoking tender to make that old ZW very expensive, add-ons notwithstanding.

My opinion:

If you are running only modern stuff, using a modern power supply is safest.  If you are running mixed old school and modern, a ZW is fine with proper protection.  I feel older stuff works better with the older power supplies.  

I run pre-war, post war and modern and my main power source is a PW ZW.  I have a ZW-C with 135 watt bricks and my PW ZW works the pullmore motors better.  I have TVS's on all outputs and I use thermal breakers that are lower in amp rating than what I want.  As an example, I use a 7.5A thermal breaker for a 10A feed and a 5A breaker for a 7.5A feed.  The slow acting nature of the thermal breakers are the reason for my choices.

As long as you use proper fuses/breakers and TVS's, the older power is fine IMHO.  Fuses located close to the power supply and TVS's as close to the track as possible.

Tony

What others have said, it's not the ZW that can't handle modern electronics, it's the modern electronics that can't necessarily handle the output of the ZW.  It's out put is not "clean" and has spikes in  it and those can kill modern stuff, at least that is my simple understanding of the situation.

I use a 275 watt PW ZW to power my modern trains and DCS and everything works just fine.

i do use a 10 Amp fast blow fuse between the transformer and the fixed in of the TIU. 

I use a 250&275 Watt ZW's for almost 15 years just put a fast blow 10 Amp fuse at each power output. Never had any problems. I believe MTH has something or did at one time about using ZW's and installing a Fast Blow 10 Amp inline fuse.

My ZW runs DCS just fine for me and has for years.

I have been running a TMCC K-Line RS-3 engine from a vintage ZW for a few years and have not experienced a problem but I would not use it to run engines with more complex electronic boards without transient voltage protection.

Dennis Holler posted:

... it's the modern electronics that can't necessarily handle the output of the ZW.  It's out put is not "clean" and has spikes in  it and those can kill modern stuff,...

The ZW is clean, pure sine wave output. The transient voltage propagation is a function of powering moving appliances(toy trains) across the medium(tracks) from which they get their electric power, and the switching of that power in various means including dirty wheels, shorted circuits, and more, and is inherent with using any power source, antique or modern.

Going to use 10 amp fast blow fuses.

Just want to make sure on the TVS. Seeing they are bipolar they can go either direction correct. Are they even marked with a negative end?  Also as mentioned above- How do you know if one fails or is failing, before you fry something. Continuity check every so often?