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I found a YouTube video on adding circuit breakers on the power lines coming from my Lionel ZW transformer. He mentioned Eaton miniature circuit breakers WMZS1C03. In going to the recommended supplier, I found that they have been discontinued.
Can anyone tell me a suitable substitute?

Thanks
 

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Basically you want a 3 amp circuit breaker. By Google I found a ZE 700 found on ebay at 4 or 3 amps for $4.99. Amazon had it for thirty! Some one like Digikey may be cheeper. If you need just one ebay is okay.
 

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You want magnetic breakers they respond instantly. Most breakers are thermal and for modern engines they don't pop fast enough when there's a short.
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If you are protecting modern engines, the fastest thing is a fuse. They are a pain to replace every time there is a short, but much less of a pain (and expense) than replacing a PC board.

I started out with 10 amp mini automotive fuses, then I added 10 amp magnetic hydraulic breakers. The fuses always beat the breakers. I switched the fuses to 15 amp and the breakers usually opened first, but not always as fast as I would have liked so I switched back to 10 amp fuses.

I should have bought these 5 amp breakers and that’s the one I would recommend if you go with breakers.
http://www.digikey.com/product-detail/en/sensata-technologies-airpax/PP11-2-5.00A-XX-V/723-1267-ND/2781056

But fuses are cheap and as I said they are fast.
http://www.digikey.com/product-detail/en/littelfuse-inc/0297010.WXNV/F991-ND/146591
 

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If you are protecting modern engines, the fastest thing is a fuse. They are a pain to replace every time there is a short, but much less of a pain (and expense) than replacing a PC board.

I started out with 10 amp mini automotive fuses, then I added 10 amp magnetic hydraulic breakers. The fuses always beat the breakers. I switched the fuses to 15 amp and the breakers usually opened first, but not always as fast as I would have liked so I switched back to 10 amp fuses.

I should have bought these 5 amp breakers and that’s the one I would recommend if you go with breakers.
http://www.digikey.com/product-detail/en/sensata-technologies-airpax/PP11-2-5.00A-XX-V/723-1267-ND/2781056

But fuses are cheap and as I said they are fast.
http://www.digikey.com/product-detail/en/littelfuse-inc/0297010.WXNV/F991-ND/146591
When I had my PW ZW, I used 10A fuses between the transformer and the track. (I think I said this in another thread) :confused: The local stereo store/Radio Shack would sell me the fuses for $.75 a piece. I tried 10A car breakers, but they didn't react as fast as the fuses. I was about to try 5A breakers, but I ended up trading in my PW ZW for a ZW-C that has fast acting breakers and now I use a Powermaster that is powered by a 180w brick with my Cab1-L TMCC and it works great in command mode and conventional.
 

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I first bought circuit breakers for my post war ZW from Scott's Odds and Ends, they were expensive compared to the next set of circuit breakers I bought from Mouser Electronics. I am now using 7 amp 120 volt breakers from www.mouserelectronics.com They cost around 3 to 4 dollars each.

Lee Fritz
 

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Thank you for the additional help.
If you are looking to protect newer engines with electronics and using an older transformer then a TVS(transient voltage suppressor) should be used as most older transformers have a very high amp breaker in them. Also a 7 or 8 amp fast acting circuit breaker would help in addition to the TVS unit.

Lee Fritz
 

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Many PW layouts use PTC devices as shown here. One for each block. They are cheap and easy to use.They reset automatically and trip quickly.

The devices shown are 4 amp hold, 8 amp trip. RUEF 400

View attachment 274314
These look interesting. I am currently running PW locos with a ZW but would like to better protection as I am interested in adding some more modern locos. How are these incorporated..... neatly? Are they better than a 3 or 4 amp circuit breaker?

Ken
 

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A PTC does not trip anywhere near as fast as a magnetic circuit breaker! It doesn't trip any faster than the commonly available thermal breakers.

RUEF400 Specification Sheet

Note below, it can take up to 12.7 seconds for the PTC to trip at 20 amps! This is slower than the cheap thermal circuit breakers. Note that this is a maximum time, but it'll still take a long time for it to trip on an overload.

__PTC.png
 

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What timing! I’ve been going through fuses like crazy while dialing in my O27/Gargraves “streets” track. So, I’ve been thinking once again about getting some breakers. On another thread (which I couldn’t find) someone said they had been using Eaton FAZ series thermal magnetic breakers. I’m thinking about using FAZ-B3-1-SP breakers (link and chart attached). They look like they will open at between 9 and 12 amps in .005 to 2 seconds. T-Man recommended a 3 amp breaker 3 years ago, but I’m not sure if that will work for me. I sometimes run postwar, but more often run modern locos. Most of my passenger cars have been converted to LED lighting, but I do still have some with incandescent lights. A PW two motor loco uses about 30 watts.

Anyone know what a modern 2 motor diesel or one motor steamer draws (with smoke on)? How about a modern passenger car with incandescent lights?

https://www.automationdirect.com/adc/search/search?fctype=adc.falcon.search.SearchFormCtrl&cmd=Search&searchquery=FAZ-B3-1-SP&categoryId=0&TxnNumber=-1&searchqty=10

eaton breaker chart.jpg
 

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So I guess PTC is out then. John I assume then that a magnetic breaker would be the way to go. Given the ZW I am using and that I am electronically challenged, what would your recommendation be as to a breaker?
 

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Correct, if you want a fast acting circuit breaker, the magnetic ones are typically the fastest. Here's a 10A one that's suitable for your situation, it'll be much faster acting than any of the thermal alternatives.

10A Magnetic Breaker for $10.
 

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Correct, if you want a fast acting circuit breaker, the magnetic ones are typically the fastest. Here's a 10A one that's suitable for your situation, it'll be much faster acting than any of the thermal alternatives.

10A Magnetic Breaker for $10.
John,

What do you think of the 3 amp version of that FAZ that I am considering? Do you think that would trip when running say two modern locos with 2 motors each, smoke on and 5 or 6 passenger cars with incandescent lights?
 

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Bob, I suspect with dual diesels with smoke and six incandescent passenger cars, you would be knocking on the door to kicking a 3A breaker. Usually, a dual diesel will be pulling around an amp or a bit more with smoke with a light load, and incandescent passenger cars are in the .3 to .4 amp range each. I noticed they didn't have anything between 3A and 10A on that site. What you're really worried about is a short circuit on a derailment or the like, right? Why not just use the 10A model?
 

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Bob, I suspect with dual diesels with smoke and six incandescent passenger cars, you would be knocking on the door to kicking a 3A breaker. Usually, a dual diesel will be pulling around an amp or a bit more with smoke with a light load, and incandescent passenger cars are in the .3 to .4 amp range each. I noticed they didn't have anything between 3A and 10A on that site. What you're really worried about is a short circuit on a derailment or the like, right? Why not just use the 10A model?
I have 10A Snapak magnetic hydraulics now, but the 10A mini fuses nearly always beat them.

They do have the FAZ breakers sized between 3 and 10 amps at automation direct. I just pulled up B4, B5 and B6 and they are all in stock.
 
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