Inline breaker

I use standard automotive 10amp fast-blow fuses. I went to the local auto parts store, and purchased 8 of those fuse holders for trailers, and a few dozen 10 amp fuses. they work fine, and have saved any number of electronics damage, including the internals of the DCS TIU devices.

I would use a 7 amp circuit breaker as they can be reset and not replaced when a short happens. Ten amps is too high for most applications. 

Lee Fritz

phillyreading posted:

I would use a 7 amp circuit breaker as they can be reset and not replaced when a short happens. Ten amps is too high for most applications. 

Lee Fritz

Well, our experience has been different. With a 12 car (or more) passenger train with all the lights on, and two powered diesel units, plus another freight train on the same main line, the Z4000 shows an amp draw of 6 to 8 amps. Thus, we use 10 amp fast-blow automotive fuses. They are easily replaced in their fuse holders, simply pull the blown one out, and plug in the new one.

If you are using an MTH Z-4000 it should already have the proper circuit breaker installed in it.

Lee Fritz

phillyreading posted:

If you are using an MTH Z-4000 it should already have the proper circuit breaker installed in it.

Lee Fritz

Well, yes they do. However, sometimes that breaker in the Z4000 STILL does not protect the TIU from damage! Thus, I added the 10 amp fast-blow automotive fuses in-line.

Hot Water posted:

phillyreading posted:

I would use a 7 amp circuit breaker as they can be reset and not replaced when a short happens. Ten amps is too high for most applications. 

Lee Fritz

Well, our experience has been different... we use 10 amp fast-blow automotive fuses...

I still cannot understand why anyone in this hobby would use a recurring consumable, with the stocking expense & hassle("oops, no train running today - we're out of fuses"), when there are so many suitable circuit breakers available that provide a much more reliable solution.

And for this application, a 2 amp breaker is much more appropriate... or even better, a Lionel 91 adjustable breaker.

A 7 amp breaker or 10 amp fuse will never trip/blow in this 4 amp max circuit.

Thank you ADCX Rob for the information regarding a 2 amp breaker is what is probably needed, can you point me in the direction of a source for something like this?  Google search is returning all sorts of stuff that does not seem to fit the need.

The best short circuit protection device I have found is a PSX  Fast reaction and easy to reset.  I believe that there is an older thread on this device.  $37.95 at    https://tonystrains.com/produc...ts/circuit_breakers/

Marty

necrails posted:

...can you point me in the direction of a source for something like this? 

I have used the Re-Cirk-It type breakers in various ratings for many years, here is a 2.5 amp type.

Hot Water posted:

phillyreading posted:

If you are using an MTH Z-4000 it should already have the proper circuit breaker installed in it.

Lee Fritz

Well, yes they do. However, sometimes that breaker in the Z4000 STILL does not protect the TIU from damage! Thus, I added the 10 amp fast-blow automotive fuses in-line.

That is a first for me, never heard that the Z-4000 would not protect a TIU. Maybe your circuit breaker in the Z-4000 is defective.

Also in my opinion a circuit breaker would be more cost effective in the long term and not need replacing every time an overload happens.

Lee Fritz

ADCX Rob posted:

necrails posted:

...can you point me in the direction of a source for something like this? 

I have used the Re-Cirk-It type breakers in various ratings for many years, here is a 2.5 amp type.

Interesting, I have never seen one of those styles of breakers before.

Lee Fritz

You may want to consider the supplemental circuit breakers Eaton manufactures.  I'm currently using 3 (one each 2A, 3A, and 4A) from their FAZ series that open on a "C" trip curve.  They are built very well and engineered very thoughtfully - and are less than $10 each.  It's also nice that they are available in 1A increments so you can really dial into your power needs.  

I'm still trying to decide if I love them - they don't open as quickly on a short as I would like, but they definitely open much faster than the thermal breaker in my Type V or ZW(R).  I might buy a "B" curve one to see if that works a bit better.

I got mine from Automation Direct - good prices, fast shipping, and lots of good info about each device.

phillyreading posted:

ADCX Rob posted:

necrails posted:

...can you point me in the direction of a source for something like this? 

I have used the Re-Cirk-It type breakers in various ratings for many years, here is a 2.5 amp type.

Interesting, I have never seen one of those styles of breakers before.

I've seen the style in pictures but never really run across a source.  After a bit of searching, these are now manufactured by Eaton Heinemann as their "KD" series.  Newark is a distributor for them - $5-10 a piece depending upon the amperage.  These are thermal breakers (which should be fine) but are a less sophisticated than the other Eaton ones I mentioned (which I believe were from Cooper before they got bought).

PTC Resettable Fuses are Protection for pennies.  I've been using them for over 10 years.

Try Hold rating of 2.5A and 3A at this Mouser page.

See in depth information on PTC Resettable Fuse uses at Circuit Protection for Toy Trains.

Interesting that you raise the idea of using polyfuses.  I had considered doing so awhile back but decided against it because a) there's no explicit feedback (other than the power being absent) that the protection has engaged, and b) they restore power automatically after cooling (whereas I wanted to control when power was restored). A good idea, though, if the above aren't a concern and/or cost is a driver.

To annunciate power being absent, you just wire an LED indicator across the PTC, obviously with the correct current limiting and polarity protection. 

OTOH, I agree with you about the automatic reset, for my track power, I want it to stay off until I figure out what happened.

The power does stay off until the fault is cleared.  To return power through the tripped PTC, turn off power supply, clear fault, and turn on power supply.  The track power indicator lights or a lighted caboose, etc are nice.

I've been using 6 Amp Polyfuses for many years, but I'm not happy with their performance, because they are slow to act. It is still possible to weld the wheels to the rails before they "blow". I think we measured it at a full 10 seconds.

I really like Rob's Re-cirk-it breakers. For my huge layout, I can place them in convenient locations to handle local tracks. So when there are derailments and they pop, the operator can easily reset them when the problem is cleared, without disturbing the rest of the layout.

I'll be getting the 2.5 A and the 5 A versions. I'll use the 2.5's for industrial and switching areas where only one engine will be in use. The 5's will be used on the mainlines to handle dual powered units (can motors) and passenger car lights (LED). 

BTW, Rob's ebay source also sells the 5 A type for $12.99 for 5 breakers, same as the 2.5's. Nice price!