tvs diodes and fast trip 3 or 5 amp inline circuit breakers or fuses.

self resetting breakers work best imho.

link http://www.modeltrainforum.com/showthread.php?t=117026&highlight=circuit+breakers

 

Thanks for the info. best to play it safe than sorry.

Harry

 

I used this 5 amp circuit breaker with my post-war ZW. It reacts instantly and resets with a push of a button. I put it in-line between the transformer and the track. I just soldered the wires to the plugs.

 

I used this 5 amp circuit breaker with my post-war ZW. It reacts instantly and resets with a push of a button. I put it in-line between the transformer and the track. I just soldered the wires to the plugs.

View attachment 402314

That is a great set up, Denny. Where did you find that circuit breaker?

Tom

 

Thanks Denny. Please keep the ideas and types coming.

Harry

 

Thanks Denny. Please keep the ideas and types coming.

I posted recently about making a box for this same purpose. I took close up pics of the parts so you can see the pics and diode part #'s. Breakers are 3A.

http://www.modeltrainforum.com/showthread.php?t=156042&highlight=breaker+box

 

Thermal Breakers are very low to react. Modern Transformers trip in under 10 milliseconds. Thermal breakers are 10 to 100 times that. If you run conventional along with command this is the best out there now. Use these along with TVS's

http://www.traintekllc.com/dcc-specialties-psx-ac-3-rail-circuit-breaker/

Pete

 

The 5 amp breakers I used reacted as fast as what comes in modern transformers. I had a couple on the club layout when we had the PW-ZW and they worked perfectly. We have a ZW-L now so they're not needed.

 

Denny, I'd have to disagree that those thermal breakers are as fast as the Lionel PH180 brick breaker. I've used tons of thermal breakers, and as Pete says, they're not lightning fast.

I looked, but I find no specs for the Zing Ear ZE-700-5 5A, so I'm assuming from the descriptions and the price they're plain garden variety thermal breakers.

 

I understand John. I'm just relating my experience with those circuit breakers. I tested them several times by jumping the third rail to the ground rail with a screwdriver before I let anyone run trains.

 

What about the breakers sold by Dallee?

https://www.dallee.com/5-Amp-Circuit-Breaker-with-Spike-Protection-1112


I'm also very interested in finding the right way to protect the electronics in my modern trains. I run mostly prewar and have 5 perfectly good ZWs, so it's hard to justify the expense of a modern transformer to run a handful of modern locos.

John

 

What about the breakers sold by Dallee?

https://www.dallee.com/5-Amp-Circuit-Breaker-with-Spike-Protection-1112

John

The Dallee Circuit Breaker with Spike Protection uses a thermal breaker and a TVS diode, and frankly, at $25 are a ripoff.

You can get 5 amp thermal breakers from Digi-Key for $2.47 here. Digi-Key has TVS diodes for $0.65 a piece here.

To the electronic wizards here, perhaps you can explain something to me:

It is my understanding that circuit breakers/fuses protect the transformer from high current and TVS diodes protect the sensitive electronics in the engine. If that is the case, shouldn't an appropriately rated thermal breaker used in conjunction with TVS diode be sufficient protection when using postwar transformers with modern locomotives?

 

In electronics fast is relative. Here is a graph of a typical thermal breaker. Some are faster but none come close to an electronic breaker.

Maybe to put in perspective. The breaker in your post war ZW is like a 50cc moped. Modern Thermal breakers might be like a 250 cc motorcycle. Fast compared to the moped. Electronic Breakers are like a Formula 1 car.

Pete

 

I originally used 10-amp blade type mini fuses. I switched to magnetic-hydraulic breakers, but I got ones that are too slow. The 10-amp fuses almost always beat the breakers, so I still rely on the fuses.

I have three (or more) questions.

How fast is fast enough? At 4 times rating, a thermal breaker will trip in .6 to 5 seconds, a magnetic-hydraulic (slow) breaker will trip in .1 to 4 seconds, a magnetic-hydraulic (fast) breaker will trip in .03 to .5 seconds and a blade fuse will blow in .08 seconds. How fast is the PSX-AC?

How much current is too much? How much current will it take to damage electronics in modern trains? Is 20 amps too much? 40?

What am I willing to pay? I like the setup that beachhead2 made, but I think those Eaton breakers go for around $50 each. I also like the PSX-AC, but they are also $50 each. I could get some faster magnetic-hydraulic breakers for around $25 each. I can get mini fuses for $.19 each if I buy 100 of them. Maybe its dumb to ask this question, since one fried circuit board costs more than 4 of the PSX-AC breakers, but I still ask.

http://www.littelfuse.com/~/media/a.../passenger-car-and-commercial-vehicle/blade-fuses/littelfuse_mini_datasheet.pdf

 

I like the setup that beachhead2 made, but I think those Eaton breakers go for around $50 each.

No, I bought them from AutomationDirect for $9.25 each (+free S&H but that was before Christmas).

https://www.automationdirect.com/adc/Shopping/Catalog/Circuit_Protection_-z-_Fuses_-z-_Disconnects/UL_1077_Rated_Supplementary_Protectors/Single_Pole_Supplementary_Protectors_(0.5A-63A,_FAZ_Series)/C_Curve_(0.5A-63A,_FAZ-CXX-1-SP)/FAZ-C3-1-SP

 

OK. That makes the Eaton breakers more attractive, but now that I have looked at their data sheet, I’m not sure. At 900% of their rating, they will trip in .003 to 3 seconds.

But I’m still wondering what guidelines need to be considered when selecting circuit protection. Theoretically, a short circuit will result in infinite amps, so maybe I should be looking at the high end of the time-current charts. If so, (at 10 times their rating) the Eaton thermal-magnetics will trip in .003 to .015 seconds, a slow magnetic-hydraulic in .010 to .3 seconds, a fast magnetic-hydraulic in .010 to .09, a thermal in .12 to .7 seconds and a mini fuse in .01 seconds.

 

Yes Matt, I seem to remember gunrunnerjohn posting something about TVS diode in-line with a 5 amp breaker awhile back.

 

Breakers and fuses also protect sensitive electronics inside modern engines from excess current.

Transformers have breakers for their own protection, but might not trip fast enough to protect engines.

TVS diodes protect electronics from voltage spikes.

 

Breakers and fuses also protect sensitive electronics inside modern engines from excess current.

In what scenario(s) would you have a high current in electronics? In the case of a short circuit from say, a derailment, the current wouldn't be going through the engine.

 

Inside the engine? Would you solder them to the roller contacts?

 

That's right. Inside. I have no idea how. GRJ will have to weigh in.

 

file:///Users/Ken/Pictures/download%20(11).png
Pic of TVS Diode

 

Doesn't the Dallee product provide both overload and voltage spike protection in one unit? Why wouldn't this be a good way to go?


John

 

The problem with the Dallee (if it is a thermal breaker as Matt said) is that it is slower than a magnetic hydraulic or a thermal magnetic, but you are paying the same price as a magnetic-hydraulic. You do get a TVS diode with it, but they are cheap and easy to install.

 

I just looked it up John that would work. $24.95 is a good price to protect you locos.

https://www.dallee.com/5-Amp-Circuit-Breaker-with-Spike-Protection-1112

https://www.dallee.com/3-Amp-Circuit-Breaker-with-Spike-Protection-1111

 

No, it's not a good price. See my earlier post in the thread. You can get a thermal breaker, which is what the Dallee circuit breakers are, and a TVS diode for $3.12 plus shipping at Digi-Key. So with the Dalleee item, you're paying $21.83 too much.

 

I'm thoroughly confused. Here's a response directly from Dallee Electronics when I asked what type of breakers they are selling:




It looks like there are several types of breakers (thermal, thermal magnetic, etc.) What type of breakers are you selling?

"These are thermal which is why they are called "mechanical circuit breaker" - as shown below in the trip graphs. Magnetic breakers can trip very fast and are not really needed for model train use. They also cost a fortune compared to standard thermal breakers (which were incorporated in most power transformers dating way back)."

 

I'm thoroughly confused.

You’re not alone there John. This thread has prompted me to reexamine the circuit protection I am using and as noted above, I still have some questions. I would be interested in seeing the trip graphs for the Dallee breaker. Do they look like the one in post #14? If so, they are overpriced. The Sensata magnetic-hydraulic ones that I got are around the same price ($25). I got 10 amp breakers and my 10 amp fuses always beat them. Maybe if I got the 5 amp magnetic-hydraulics, they would be faster than the fuses.

 

Just to confuse slightly more, here are some alternative protective devices that have not yet been discussed, PTC and eFuses.

View attachment AND9513-D.PDF

 

Yesterday I went to my local electronics store and asked what they had for circuit breakers. They had the exact breakers Denny posted earlier in this thread, so I bought a 5-amp and a 10-amp. I did a little experiment with them, along with my ZW and a modern MTH Z750. Here are the trip times:

ZW internal breaker: 3.79 seconds
ZW with external 10A breaker: 2.95 seconds
ZW with external 5A breaker: 1.12 seconds
MTH Z4000 internal breaker: .43 seconds

How fast is needed for adequate protection?

 

I would want something like the Z4000.
Back when DCS came out (spring 2003?), I got it right away and (this is before the better made VL TIUs) fried 2 TIUs before the ZW breaker tripped.

I then added in line 10 amp fuses (which were a pain).

Peter

 

John, the faster the better.

How did you provide a load to test the trip times?

 

I turned the track power up to 12 volts, then connected a wire between the center and outer rail. From that, I documented the trip time of the ZW internal breaker. Then, I spliced-in the 5-amp breaker and then the 10-amp breaker.

I did the same thing with the MTH transformer, and its breaker tripped the fastest.

From what I can tell, if I'm going to continue using the ZW, I need to do 2 things:
1: Add external circuit breaker, but which kind?
2: Add TVS, but how many, and where?
Is this correct?

John

 

I'd like to get back to a question that Matt_GNo27 asked back on page 4 that doesn't seem to have been addressed.

There's been a lot of ink spread regarding the size, speed and type of these "secondary" breakers, but I'm still trying to understand why they're needed. Under what conditions? What TYPE of short are they protecting against?

I agree with the use of TVSs to suppress surges that can harm electronics, but I'm coming up short on what the secondary breakers are protecting and why.

Examples, please.

 

Has anyone wired up a ZW to a Lionel Powerhouse Lockon 6-22914 for tubular track? The lockon is designed to be powered by a Lionel Power House but why wouldn't a ZW work too? There is the issue of adapting the two wires from the ZW to the 3 connector plug in the Powerhouse Lockon. I believe the outside connectors are used for power input.

 

Taylor, that is for a Lionel Powerhouse. You need a regular lockon or solder the wires directly to the track. Keep in mind the U terminals should be connected to the outside rail and the A, B, C or D terminals the center rail.

 

The TMCC Direct Lockon is designed specifically for constant voltage command operation. Also, it stomps on the DCS signal, so it's not compatible with MTH PS2/3 locomotives.