Circuit protection

There are a couple of inexpensive options that would offer very good protection.  One would be the Lionel 91 Circuit Breaker.  Another would be an Airpax Instant Circuit Breaker.  Both are simple to operate, but neither has a built in trip indicator light.  However, an incandescent bulb could easily be wired in parallel with the breaker.  It would only illuminate when the breaker trips.  If you decide to use an Airpax breaker, it and the light could be mounted inside a small box, if desired.

Thanks to Steve’s advice I replaced my inline fuses with the Airpax Instant Circuit Breakers. I use a PW ZW with TVS diodes to run Legacy and can say they work great. It sure beats replacing fuses.

@SteveH posted:

...neither has a built in trip indicator light...

The 91 has a # 53 bulb trip indicator.

I just installed these on my layout. I'm using a KW to power two loops. The small rocker switch pops out exposing a white bar to indicate that it tripped.

https://www.mouser.com/Product...Bmg8fZQA64NMU4tFFjku

The plates are standard Leviton Decora modular communication port plates. Everything would fit in a plastic electrical box.

@RSJB18 posted:

I just installed these on my layout. I'm using a KW to power two loops. The small rocker switch pops out exposing a white bar to indicate that it tripped.

https://www.mouser.com/Product...Bmg8fZQA64NMU4tFFjku

I have been successfully using these for many years although I use the 5 amp version. These are the same ones that were recommended by Jim Barrett in his OGR video. Your use of the Leviton port plate is definitely a novel mounting method!

@RSJB18 posted:

I just installed these on my layout. I'm using a KW to power two loops. The small rocker switch pops out exposing a white bar to indicate that it tripped.

https://www.mouser.com/Product...Bmg8fZQA64NMU4tFFjku

The performance of those breakers is not that great, especially compared to the aforementioned AirPax:

Also, if you short a wire that will carry less than 5 amps, you will melt the wire before tripping the breaker. I can instantly trip my 10 amp Airpax with a 28 awg wire.

@bmoran4 posted:

The performance of those breakers is not that great, especially compared to the aforementioned AirPax:

I'm sure there are better on the market. These will do for my present layout.

@RSJB18 posted:

These will do for my present layout.

If you are good with measuring trip time in seconds, sure!

@ADCX Rob posted:

The 91 has a # 53 bulb trip indicator.

Thanks Rob, I saw some Ebay listings for "Lionel 91" breakers, some had lights and some did not appear to have one.  For Example:

@tstark posted:

I have a 8 x8 two loop Connected  layout for the grandson. I intend to run 2 lion chief + engines. I have the temp layout on my family room floor. Looking for circuit protection . I am powering off 1 side of a kw. I noticed that the protector on the z1000 trip quickly. I don’t know what size they are. I need something simple that I can explain to my son and 9 year old grand son how to reset. Some thing with a alert light if possible. I might use the other side of the kw for lights and accessories if they don’t over tax the kw. I really would appreciate any advice but I would like to keep it simple for him to understand.
thanks, tstark

@tstark emailed to SteveH:

Sent from my iPad
Thanks for your help. I will use the air pac units. They are not expensive . Should I get one for the track supply , another for the accessories and one for all the layout lights.would the7.5 amp be okay. I am more concerned with eliminating a fire hazard
Thanks again, Tstark

Thomas, If I've understood your request correctly, you will be powering your layout with the KW, right?

The KW can deliver about 8 Amps total, so one or more 7.5Amp breaker(s) would be the largest available safe value for an Airpax Instant breaker and should work well.  Using three of them, one for track, one for accessories, and one for lights would be ideal.

7.5 Amp   PP11-0-7.50A-OC-V   https://www.onlinecomponents.c...50aocv-10090644.html

Airpax Instant - trip "curve"

@SteveH posted:

Thanks Rob, I saw some Ebay listings for "Lionel 91" breakers, some had lights and some did not appear to have one.  For Example:

That one has a light... as they all do.

Since we are discussing the electromagnetic #91 breakers, @PLCProf has tested them respond very quick (4-5ms):

https://ogrforum.com/...it-breaker-trip-time

I have this little guy sitting on my workbench.  Whenever I'm testing something that I'm not sure if it's going to suck up excess current and cook, I wire him in to the loop.  They do work really well.  It trips at about 3 amps on the low terminal, and 4.5 amps on the high terminal.  A direct short trips it very quickly!

@ADCX Rob posted:

That one has a light... as they all do.

Rob, thanks again for the clarification.  So, is the bulb under the (translucent?) red button?

Yes, under the button.