Electrical Protection of a conventional layout

I recommend using simple TVS units directly across the track feeder lines. 

 

I found that Scott's TVS unit was not well suited to our train applications.  I analyzed a unit a few years ago, and even talked with Scott and a representative from the manufacturer, but I still believe that the unit they had at that time was not suitable for our floating AC systems.  Their technology was geared for protecting long ground-referenced communications lines such as telephone lines feeding a modem.

Dale's suggestion to look at allelectronics is good idea. You will find well priced Euro strips there. Then from other electronic providers, get the TVS, a few bends into the strip and you can easily connect them to your tracks. There are posts - or were in the old forum - that showed pictures of them implemented... maybe someone saved the picture, but it is relatively simple. The nice thing about the EU strips is you can cut them down to the size appropriate for your need.  Scotts is a good place, not disparaging to him, but these were made for alarm systems.  You can buy them on the internet for 1/2 the price, but they do no more than the 50cent TVS from Mouser.

 

Chew on it.

 

Ralph

I went to the All electronics site but could not find the circuit breakers there. I have sent them an email asking if they still carry them and what the link is. I have not heard back from them as of yet.

 

I am looking at building something very much like Dale's link now. The price savings alone will allow me to purchase more track, switches and other things. The other advantage I have is my father although 92 years old is a very talented cabinet maker. He is always looking for small projects to work on and something like this would be perfect. No offense to Dale but what he comes up with will be furniture grade so I will have the best of both worlds! Good looks and protection for my layout.

 

Any other wiring things I need to consider? Anything special for my switches? I will be using Ross switches and Gargraves track. The switches I currently own have the DZ-1000 switch motors.

TVS are dirst cheap compared to blown up electronics board.  I have them across my transformer and right where the feeders connect to track AND in locos as I take them apart for battery change out or lubrication.  So far so good with crossed fingers.

If allelectronics is out of them (ask for P/N CB-010 listed in their catalog, their phone number is 1-888-826-5432) here is a thermal one,one of many 10 amp breakers  Mouser lists. This one is 2 bucks. The purpose of the breaker is to protect the wire IMO,not the device run. Of course you can spend more for something faster to protect thin gauge branch lines but these are fast enough IMO to protect the wire in most cases.

 

http://www.mouser.com/ProductD...2bX3hdK2dc9CCKmV4%3d 

 

 Perhaps Dale M can look through the list at MOuser and find something better.

 

Dale H

DPG

So far Dale H and Dale M have given sound advice. Pick up on the comment that the TVS protects the wire. The TVS will capture the spike and diffuse it and keep it from spreading. Excuse my basic english, not electrician jargon. It may not protect electronics in the engines you run. That level of protection requires much more and the mfgr's should be providing that, but they don't.

 

If you are using DZ100's, they are reliable, but you need consider how you will operate them. There is an active post about this subject right now, read thru it and it may help you.

 

https://ogrforum.com/d...ent/4949358381195911

 

Ralph

I put a TVS in each engine across the track pickups.  IMO, it's the best place for protecting the individual electronics of that engine.  I also have one across the track feed.

 

The TVS does nothing to protect the wire from short circuit current, it's contribution is to suppress high voltage spikes that can damage electronics.

 

I agree with Ralph in that it's not perfect protection, but it's way better than what is provided by the manufacturer.

I hope that it is alright for me to ask a related question here.

 

I have 3 PW ZWs and I use all 6 throttles. The commons are part of a bus wiring setup. I am not sure how to include the TVS in this arrangement. I can connect one end to a ZW power post, but what about the other side. I can connect to the ZW common that the throttle belongs to but there are many paths to common besides the one in this particular ZW.

 

Cheers

Denny

 

Denny

The wires on a TVS are very easy to bend. Wire them[6] between "A" and "U"and, "D" and "U" on all three pw ZWs. The TVS is wired as if "shorting" the circuit but of course it will not short it. They can also be wired at a terminal distribution strip if the ZW binding posts do not suit you.

Thanks Dewey,

I had considered this but didn't know for sure if it would give me the needed protection. I will follow your TVS leads : tomorrow.

Cheers

Denny

Why is it necessary to use the TVS? I understand you are trying to stop voltage spikes but I have never had the problem of spikes of any kind. I run both MTH's DCS and Legacy. I run all top of the line engines from both, am I missing something here? Should I use the TVS? I have been in O gauge since 1975 and have built several layouts and have never had voltage spikes the likes that some of you have purported to have. I know quite a few of layout builders in my area and none do what you guys are suggesting. Please explain why it should be done and why it does not seem to be a problem in my sphere of friends.

Why do you have insurance on home car etc?  Sure nothing may never happen, but if it did, you are glad the insuance was there.  Same here, you may never encounter a board killing voltage spike, but if things happen, as Murphy's law predicts, then you will be glad the TVS insurance was there to take the hit(s).

The exact cause of voltage spikes and if they will kill your TMCC or DCS locomotives is still uncertain, too many variables. But there have been enough unlucky operators to determine the need for a TVS. I suspect that the majority of train operators are just like you. Never had a problem and likely never will. But that doesn't mean it can't happen. It's kinda like the Firestone tire problem 10 years ago. Not everyone with Firestone tires experienced tire problems that caused their vehicle to crash. But there were enough unlucky drivers to determine the need for a recall. A TVS is far less expensive than a new set of tires and less expensive than a new locomotive or repair. A TVS is just an added layer of protection that is also very inexpensive and easy to add to your existing layout.

I have personally been putting a TVS diode into each locomotive as I open them for other purposes.  I also have one across the transformer feed, a belt-and-suspenders approach.

 

I worked for many years in aerospace equipment design, and transient protection was mandatory for the equipment.  No protection usually resulted in a quick demise of the unit under test!

 

Look at it this way, it can't possibly hurt, and it's very likely to help.

Maybe you have a TVS and don't know it.  Don't at least some of the MTH TIUs have a TVS?